Installation and

Service Instructions
for use by heating contractor

Vitotronic 100, Model GC1

Digital boiler control unit
Please file in Service Binder

VITOTRONIC 100, GC1

IMPORTANT
Certified as a component part Read and save these instructions
of Viessmann boilers only
for future reference.

5351 338 v1.8 10/2013 1

General information

Safety, Installation and Warranty Requirement

Please ensure that this manual is read and understood before commencing installation. Failure to comply with the issues
listed below and details printed in this manual can cause product/property damage, severe personal injury, and/or loss of
life. Ensure all requirements below are understood and fulfilled (including detailed information found in manual subsections).

Licensed professional heating Advice to owner

contractor Once the installation work is complete,
The installation, adjustment, service, the heating contractor must familiarize
and maintenance of this equipment the system operator/ultimate owner
must be performed by a licensed with all equipment, as well as safety
professional heating contractor. precautions/requirements, shut-down
procedure, and the need for

Please see section professional service annually before the
entitled “Important heating season begins.
Regulatory and
Installation
Requirements.”

Warranty
Information contained in
this and related product
Product documentation documentation must be
Read all applicable documentation read and followed. Failure
before commencing installation. Store to do so renders warranty
documentation near boiler in a readily null and void.
accessible location for reference in the
future by service personnel.

For a listing of
applicable literature,
please see section
entitled “Important
Regulatory and
Installation Requirements.”

5351 338 v1.8

2
 General information

Safety, Installation and Warranty Requirement (continued)

Safety Terminology
Take note of all symbols and notations intended to draw attention to potential hazards or important product information.
These include ”WARNING”, ”CAUTION”, and ”IMPORTANT”. See below.

DANGER
Indicates an imminently hazardous
situation which, if not avoided, will
result in death, serious injury or
substantial product / property damage.

WARNING
Indicates an imminently hazardous
situation which, if not avoided, could
result in death, serious injury or
substantial product / property damage.

CAUTION
Indicates an imminently hazardous
situation which, if not avoided, may
result in minor injury or product /
property damage.

IMPORTANT
Helpful hints for installation, operation
or maintenance which pertain to the
product.
5351 338 v1.8

3
Product Information

Vitotronic 100, GC1

For installation on Viessmann Applicable to the following control units:
boilers only. Part No. 7134 553/7134 554/7511361, from Serial No. 7143 002

This document describes the Vitotronic 100, GC1 as used in

a single-boiler application and a multi-boiler system with an external building
automation system.

These instructions are not required for the Vitotronic 100, GC1 used in multi-boiler
systems with the Vitocontrol-S, VD2/CT3/CM2.

5351 338 v1.8

4
 Index
Page

General Information Safety Instructions and Warranty Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Product Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Heating System Types Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Circuit Diagrams 1 to 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Installation Mounting the Front Part of the Control Unit (VD2/VD2A/CT3 only) 37
Opening the Control Unit (VD2/VD2A/CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Control and Junction Box Installation Instructions (CM2 only) . . . . . . . . . . . 39
Mounting the Front Part of the Control Unit (CM2 only) . . . . . . . . . . . . . . . . . . . . . . 40
Opening the Control Unit (CM2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Overview of Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Overview of Electrical Connections (VD2/VD2A/CT3 only) . . . . . . . . . . . . . 43
Overview of Electrical Connections (CM2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Routing and Strain Relief of Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Inserting the Boiler Coding Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Setting of the Fixed High Limit (if required) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Setting of the Adjustable High Limit (if required) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Sensor Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Connection of the Boiler Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Connection of the DHW Tank Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Connection of the Return Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Connection of the Flue Gas Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Connection of the Pumps (VD2/VD2A/CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Connection of the Pumps (CM2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Connection of Return Mixing Valve or
Isolation/Modulating Valve (VD2/VD2A/CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Connection of Return Mixing Valve or
Isolation/Modulating Valve (CM2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Making Space for Accessory Adaptors on the Din Rail (CM2 only) . 58
Vitotronic 100, GCI with 30% LTP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Connection of External Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Connection of External Controls (VD2/VD2A only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Connection of External Controls (CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Connection of Combustion Air Device (VD2/VD2A/CT3 only) . . . . . . . 66
Connection of Combustion Air Device (CM2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Connection of Combustion Air Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Connection of Combustion Air Device on Multiple Boiler Systems 69
Connection of Single Air Device on Multiple Boiler Systems . . . . . . . . 70
Connection of Combustion Air Damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Gas Flue Temp. Sensor (Optional for CM2 equipped with
SS Flue Collector) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Connection of Low Water Cut-off Device (VD2/VD2A/CT3 only) 73
Connection of Low Water Cut-off Device (CM2 only) . . . . . . . . . . . . . . . . . . . . . . 74
Connections to Terminal aBÖ (VD2/VD2A/CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . 75
Connection of the Compiled Failure Alarm Indicator
(VD2/VD2A/CT3 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Connection of the Compiled Failure Alarm Indicator (CM2 only) . 77
Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only) 78
Power Supply Connection to Boiler Control (VD2/VD2A/CT3 only) . . 82
Burner Connection, Burner Control Wiring (CM2 only) 83
5351 338 v1.8

5
Start-up Procedure (overview) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Scanning Service Information Overview of Service Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Temperatures, Boiler Coding Cards and Scans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Scanning Service Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Scanning and Resetting the Service Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Troubleshooting Troubleshooting Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Functional Description Boiler Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Heating Circuit Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
DHW Tank Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Additional Information Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Coding 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Coding 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

5351 338 v1.8

6
 Heating system types

Overview

Circuit System type Boiler Key features Page

diagram
11 Single-boiler Vitorond 200, VD2A With Therm-Control, single-boiler with 3-way mixing 8
system valve
12 Multi-boiler Vitorond 200, VD2A With Therm-Control, multi-boiler with 3-way mixing 10
system valve
13 Single-boiler Vitorond 200, VD2 Shunt pump for elevating the return temperature 11
system
14 Single-boiler Vitorond 200, VD2 Shunt pump and return valve for elevating the 13
system return temperature
15 Multi-boiler Vitorond 200, VD2 Shunt pump for elevating the return temperature for 16
system each boiler
16 Multi-boiler Vitorond 200, VD2 Common supply pump and low-pressure manifold 17
system
17 Multi-boiler Vitorond 200, VD2 Return valve for return temperature protection 19
system
8 Multi-boiler Vitorond 200, VD2 Low-loss header and return valve for elevating 21
system the return temperature
9 Single-boiler Vitocrossal 300 Several heating circuits and one mixing valve heating 23
system circuit
10 Single-boiler Vitocrossal 300 Several heating circuits and one mixing valve heating 25
system circuit
11 Multi-boiler Vitocrossal 300 Several heating circuits and one mixing valve heating 27
system circuit
12 Multi-boiler Vitocrossal 300 and Several heating circuits, one mixing valve heating 29
system Vitorond 200 circuit and Vitorond with shunt pump
13 Multi-boiler Vitocrossal 300 and Return valve, several heating circuits and one mixing 31
system Vitorond 200 valve heating circuit
14 Single-boiler Vitocrossal 200 Several heating circuits and one mixing valve heating 33
system circuit
15 Multi-boiler Vitocrossal 200 Several heating circuits and one mixing valve heating 35
system circuit
5351 338 v1.8

7
Heating system types

Circuit Diagram 1

Single-boiler system with Therm-Control and three-way mixing valve

in conjunction with Vitorond 200, VD2A

A Heating circuit with mixing valves

B DHW tank

Plug fÖ Power supply, 120 VAC

! Outdoor temperature sensor sÖM2 Heating circuit pump, mixing 60 Hz
(only for Vitotronic 300) valve (only for Vitotronic 300) Install the main isolator in
?M2 Flow temperature sensor, sÖM3 Heating circuit pump, mixing accordance with regulations
mixing valve (only for the valve (only for Vitotronic 300) fA Burner (stage 1)
Vitotronic 300) sÖA1 Closing the mixing valves with gSM2 Mixing valve motor (only for
?M3 Flow temperature sensor, external heating circuit control Vitotronic 300)
mixing valve (only for units gSM3 Mixing valve motor (only for
Vitotronic 300) sA DHW primary pump Vitotronic 300)
§ Boiler water temperature sK DHW circulation pump (only lÖ Burner
sensor for the Vitotronic 300) (burner stage 2 / mod.)
% DHW tank temperature sensor aVD/aVH External connections
(accessory for the Vitotronic
5351 338 v1.8

100) Please refer to the control

aJA Therm-Control temperature manual Vitotronic 300 GW2.
sensor

8
 Heating system types

Circuit Diagram 1 (continued)

Wiring diagram
Wiring of the Therm-Control in heating
systems with heating circuit control units
are not connected to the boiler control
unit via the LON.
Required coding:
Change “4C” to “2” - use the plug-in
connector 20 A1 to close the
downstream mixing valve. Change “0D”
to “1” - the Therm-Control acts on the
mixing valve of the downstream heating
circuits (for Vitotronic 200 and 300,
delivered condition).

sÖ A1 Close mixing valves

A Contactor relay, field supplied
B Heating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
5351 338 v1.8

9
Heating system types

Circuit Diagram 2
Multi-boiler system with Therm-Control and three-way mixing valve
in conjunction with Vitorond 200, VD2A

LON LON connection (available connections with terminator)

A Heating circuit with mixing valves
B DHW tank

Plug aJA Therm-Control temperature gSM2 Mixing valve motor (only for
! Outdoor temperature sensor sensor Vitotronic 300-K)
(only for Vitotronic 300-K) sÖM2 Heating circuit pump, mixing gSM3 Mixing valve motor (only for
?Flow Flow temperature sensor, valve (only for Vitotronic Vitotronic 300-K)
common heating flow (only for 300-K) gSM3 Mixing valve motor, Vitotronic
the Vitotronic 300-K) sÖM3 Heating circuit pump, mixing 200-H
?M2 Flow temperature sensor, valve (only for Vitotronic lÖ Burner
mixing valve (only for the 300-K) (burner stage 2 / mod.)
Vitotronic 300-K) sÖ Heating circuit pump Vitotronic aVD/aVH External connections
?M3 Flow temperature sensor, 200-H
mixing valve (only for the sK DHW circulation pump (only
Vitotronic 300-K) for the Vitotronic 300-K) Please refer to the control
? Flow temperature sensor fÖ Power supply, 120 VAC manual for the Vitocontrol-S,
5351 338 v1.8

Vitotronic 200-H 60 Hz VD2/CT3.

§ Boiler water temperature Install the main isolator in
sensor accordance with regulations
% DHW tank temperature sensor fA Burner (stage 1)
(only for Vitotronic 300-K) gSA1 Motorized butterfly valve

10
 Heating system types

Circuit Diagram 3

Single-boiler system with shunt pump for elevating the return temperature
in conjunction with Vitorond 200, VD2

C C
A1

29
20

T2
21 17B
5 17A
3
143
146
40

41
90

T1

*1
B A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor sL Shunt pump
B Domestic hot water tank % DHW tank temperature sensor fÖ Power supply connection,
C Heating circuit with mixing valve (accessory) 120 VAC
aJ A Temperature sensor T1 fA Burner (1st stage)
aJ B Temperature sensor T2 lÖ Burner (2nd stage/modulating)
sÖ A1 Close mixing valves with aVD Connection of external
external heating circuit equipment (see page 60)
controls aVH Connection of external
sA DHW pump equipment (see page 60)
5351 338 v1.8

*1 On the Vitorond the boiler supply and return are at the rear of the boiler.

11
Heating system types

Circuit Diagram 3 (continued)

Possible applications When the return temperature falls Temperature sensor T1

Heating systems with manifold below the required minimum value, Wiring of the temperature sensor T1
arranged close to the boiler. The boiler the temperature sensor T2 switches in heating systems with heating
water supply is required to be reduced. on the shunt pump. If the minimum circuit control units which are not
return temperature is not reached connected via the LON BUS to the
despite raising the return temperature, boiler control unit.
IMPORTANT the supply must be reduced by at Coding required: ”4C: 2” – use plug
least 50% via the temperature sÖ for closing the mixing valves of
This circuit diagram represents a sensor T1. the heating circuits connected
recommendation only. It is the downstream.
responsibility of the customer and/or The shunt pump must be sized so
heating contractor to check that this that bypassed water accounts for
recommendation is complete and fully approx. 30% of the total supply rate
functional. Three-phase equipment of the boiler.
must be connected via additional
power contactors.

sÖ A1 Close mixing valves

A Contactor relay, field supplied
B Heating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: 2”
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T2 at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8

12
 Heating system types

Circuit Diagram 4

Single-boiler system with shunt pump and return valve for elevating the return temperature
in conjunction with Vitorond 200, VD2

C C

A1

29
52

T2

21 17B
5 17A
3
143
146
40

41
90

T1

*1
B A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor fÖ Power supply connection,
B Domestic hot water tank % DHW tank temperature sensor 120 VAC
C Heating circuit with mixing valve (accessory) fA Burner (1st stage)
aJ A Temperature sensor T1 gS A1 Mixing valve motor for raising
aJ B Temperature sensor T2 the return temperature
sA DHW pump lÖ Burner (2nd stage/modulating)
sL Shunt pump aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
5351 338 v1.8

*1 On the Vitorond the boiler supply and return are at the rear of the boiler.

13
Heating system types

Circuit Diagram 4 (continued)

Possible applications When the return temperature falls

Heating systems in which there is no below the required minimum value,
facility for making modifications or the temperature sensor T2 switches
adjustments to the heating circuits on the shunt pump. If, as a result,
connected downstream, e.g. old the required minimum return
systems or market gardens. temperature is not reached, the return
valve is proportionally closed via the
temperature sensor T1 and the
IMPORTANT minimum return temperature is
assured.
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: 2”
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
0C: 4 Set coding ”0C: 1” for continuous –––
return temperature control
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T2 at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8

14
 Heating system types

Circuit Diagram 5

Multi-boiler system with shunt pump for elevating the return temperature for each boiler
in conjunction with Vitorond 200, VD2

C C

3 3
17B T2 17B T2
17A 17A
52 A1

52 A1
143
146

143
146
41

41
40

90
29

40

90
29

T1 T1

B A A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor gS A1 Motorized isolation valve
B Domestic hot water tank aJ A Temperature sensor T1 lÖ Burner (2nd stage/modulating)
C Heating circuit with mixing valve aJ B Temperature sensor T2 aVD Connection of external
sL Shunt pump equipment (see page 60)
fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
fA Burner (1st stage)
5351 338 v1.8

15
Heating system types

Circuit Diagram 5 (continued)

Possible applications When the return temperature falls Temperature sensor T1

Heating systems with manifold below the required minimum value, Wiring of the temperature sensor T1
arranged close to the boiler. The boiler the temperature sensor T2 switches in heating systems with heating
water supply is reduced via the on the shunt pump. If the minimum circuit control units which are not
motorized isolation valve. return temperature is not reached connected via the LON BUS to the
On multi-boiler systems without the despite raising the return temperature, boiler control unit.
Vitotronic 333, the cascade and DHW the supply must be reduced by at Coding required: ”4C: 2” – use plug
tank control must be activated by a least 50% via the temperature sÖ for closing the mixing valves of
building automation system. sensor T1, through the isolation the heating circuits connected
valve or the heating circuit controls. downstream.

IMPORTANT The shunt pump must be sized so

that bypassed water accounts for
This circuit diagram represents a approx. 30% of the total supply rate
recommendation only. It is the of the boiler.
responsibility of the customer and/or
heating contractor to check that this The boiler is assured optimum
recommendation is complete and fully protection in conjunction with control
functional. Three-phase equipment of the heating circuits via the
must be connected via additional Vitotronic 050 connected to the
power contactors. boiler control unit. No further
protective measures are required on
site.

sÖ A1 Close mixing valves

A Contactor relay, field supplied
B Heating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T2 at
plug aJB;
5351 338 v1.8

Coding is automatically changed to ”4b: 1”

16
 Heating system types

Circuit Diagram 6

Multi-boiler system with common supply pump and low-pressure manifold

in conjunction with Vitorond 200, VD2

C C

3 3
17A T1 17A T1
52 A1

52 A1
143
146

143
146
41

41
40

90

40

90

B A A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor lÖ Burner (2nd stage/modulating)
B Domestic hot water tank aJ A Temperature sensor T1 aVD Connection of external
C Heating circuit with mixing valve fÖ Power supply connection, equipment (see page 60)
D Common supply pump 120 VAC aVH Connection of external
fA Burner (1st stage) equipment (see page 60)
gS A1 Motorized isolation valve
5351 338 v1.8

17
Heating system types

Circuit Diagram 6 (continued)

Possible applications When the return temperature falls Temperature sensor T1

Where the manifold is arranged in below the required minimum value, Wiring for reducing the supply via
distant substations (> 20 m). The the mixing valves are partially or fully temperature sensor T1 in heating
heat transferred to the heating circuits closed via the temperature sensor T1. systems with heating circuit control
is required to be reduced. The common supply pump must be units which are not connected via
On multi-boiler systems without sized on the basis of 110% of the total the LON BUS to the boiler control unit.
Vitotronic 333, the boiler staging and supply Btu/hr output rate of the heating Coding required: ”4C: 2” – use plug
DHW tank control must be activated by system. sÖ for closing the mixing valves of
a building automation system. the heating circuits connected
The common supply pump is activated The boiler is assured optimum downstream.
by the master control of the building protection in conjunction with control
management system. It must be of the heating circuits via a Vitotronic
switched on when a boiler is engaged. 050 connected to the boiler control
unit. No further protective measures
are required on site.
IMPORTANT
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully sÖ A1 Close mixing valves
functional. Three-phase equipment A Contactor relay, field supplied
must be connected via additional B Heating circuit controls
power contactors. connected downstream
Switch contact closed: signal
for ”close mixing valve”
C Power supply connection,
120 VAC
D Junction box, field supplied

If an external cascade control unit is

used, the distributor pump must be
connected to the external control unit.
Available system accessories

Flue gas temperature sensor

Coding of system type Change required Automatic change

01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
0d: 2 Set coding ”0d: 1” –––
Therm-Control is effective for the mixing
valves of the heating circuits connected
downstream
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
5351 338 v1.8

18
 Heating system types

Circuit Diagram 7

Multi-boiler system with return valve for return temperature protection

in conjunction with Vitorond 200, VD2

C C

3 3
17A 17A
52 A1

52 A1
143
146

41

143
146
41
40

90
29

40

90
29

T1 T1

B A A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor lÖ Burner (2nd stage/modulating)
B Domestic hot water tank aJ A Temperature sensor T1 aVD Connection of external
C Heating circuit with mixing valve sL Boiler circuit pump equipment (see page 60)
fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
fA Burner (1st stage)
gS A1 Return valve
5351 338 v1.8

19
Heating system types

Circuit Diagram 7 (continued)

Possible applications When the return temperature falls

E.g. old systems or systems in market below the required minimum value,
gardens and/or systems in which there the 3-port mixing valve on the boilers
is no facility for making modifications is proportionally closed via the
or adjustments to the heating circuits temperature sensor T1, thereby
connected downstream. assuring protection of the boiler.
The cascade and DHW tank control
must be activated by a building The boiler and the heating circuits
automation system. downstream are hydraulically
decoupled. The supply temperature
is controlled via the common
IMPORTANT temperature sensor.

This circuit diagram represents a

recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
0C: 4 Set coding ”0C: 1” for continuous return –––
temperature control
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4d: 1 Set coding ”4d: 2” for boiler circuit pump –––
at plug sL
5351 338 v1.8

20
 Heating system types

Circuit Diagram 8

Multi-boiler system with low-loss header and return valve for elevating the return temperature
in conjunction with Vitorond 200, VD2

C C

3 3
17A 17A
52 A1

52 A1
143
146

41

143
146
41
40

90
29

40

90
29

T1 T1

B A A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor lÖ Burner (2nd stage/modulating)
B Domestic hot water tank aJ A Temperature sensor T1 aVD Connection of external
C Heating circuit with mixing valve sL Boiler circuit pump equipment (see page 60)
D Low-loss header fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
fA Burner (1st stage)
gS A1 Return valve
5351 338 v1.8

21
Heating system types

Circuit Diagram 8 (continued)

Possible applications When the return temperature falls

E.g. old systems or systems in market below the required minimum value,
gardens as well as systems in which the return valve on the boilers is
there is a lack of clarity in the hydraulic proportionally closed via the
installation and/or systems where there temperature sensor T1, thereby
is no facility for making modifications assuring protection of the boiler.
or adjustments to the heating circuits
connected downstream. The supply temperature is controlled
The cascade and DHW tank control by the temperature sensor in the
must be activated by a building low-loss header.
automation system.

CAUTION
IMPORTANT The boiler circuit pumps on each
boiler must be sized so that their
This circuit diagram represents a supply is at least equal to the
recommendation only. It is the maximum possible total heating
responsibility of the customer and/or circuit supply.
heating contractor to check that this Recommendation: 110%.
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
03: 0 Set coding ”03: 1” for oil-fired operation –––
(re-setting is not possible)
0C: 4 Set coding ”0C: 1” for continuous return –––
temperature control
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4d: 1 Set coding ”4d: 2” for boiler circuit pump –––
at plug sL
5351 338 v1.8

22
 Heating system types

Circuit Diagram 9

Several heating circuits and one mixing valve heating circuit

Single-boiler system with Vitocrossal 300

C C

21 3
5
143
146
40

41
90

B D A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor fA Burner (1st stage)
B Domestic hot water tank % DHW tank temperature sensor lÖ Burner (2nd stage/modulating)
C Heating circuit with mixing valve (accessory) aVD Connection of external
D Neutralizing unit sA DHW pump equipment (see page 60)
fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
5351 338 v1.8

23
Heating system types

Circuit Diagram 9 (continued)

IMPORTANT The Vitocrossal 300 is operated with

constant boiler water temperature by
This circuit diagram represents a means of the boiler control unit.
recommendation only. It is the Two-stage or modulating burners
responsibility of the customer and/or can be controlled.
heating contractor to check that this
recommendation is complete and fully The boiler water temperature which is
functional. Three-phase equipment established in the heating mode is
must be connected via additional higher than the maximum heating
power contactors. system supply temperature by an
adjustable difference.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: 2”
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0C: 4 Set coding ”0C: 0” –––
0d: 2 Set coding ”0d: 0” –––

5351 338 v1.8

24
 Heating system types

Circuit Diagram 10

Single-boiler system with several heating circuits and one mixing valve heating circuit
in conjunction with Vitocrossal 300

E
C D
F
A1
20

21

or
3
5
143
146
40

41
90

B G A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor fÖ Power supply connection,
B Domestic hot water tank % DHW tank temperature sensor 120 VAC
C Heating circuit with mixing valve (accessory) fA Burner (1st stage)
D Mixing valve heating circuit sÖ A1 Close mixing valves with lÖ Burner (2nd stage/modulating)
or external heating circuit controls aVD Connection of external
E Underfloor heating circuit with sA DHW pump equipment (see page 60)
mixing valve aVH Connection of external
F Limit thermostat (max. limit) equipment (see page 60)
G Neutralizing unit
5351 338 v1.8

25
Heating system types

Circuit Diagram 10 (continued)

Possible applications The Vitocrossal 300 is operated with

For heating circuits with different constant boiler water temperature by
temperatures. means of the boiler control unit.
Two-stage or modulating burners can
be controlled.
IMPORTANT
The Vitocrossal 300 has two return
This circuit diagram represents a connections. The heating circuits with
recommendation only. It is the the higher return temperature are
responsibility of the customer and/or connected to the return connection at
heating contractor to check that this the top, those with the lower
recommendation is complete and fully temperatures to the return connection
functional. Three-phase equipment at the bottom.
must be connected via additional
power contactors. Please note:
At least 15% of the take-off from the
rated output must be connected to the
return connection at the bottom.

The boiler water temperature which is

established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: 2”
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0C: 4 Set coding ”0C: 0” –––
0d: 2 Set coding ”0d: 0” –––
5351 338 v1.8

26
 Heating system types

Circuit Diagram 11

Multi-boiler system with several heating circuits and one mixing valve heating circuit
in conjunction with Vitocrossal 300

C C

3 3
52 A1

52 A1
143
146

143
146
41

41
40

90

40

90

B D A D A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor aVD Connection of external
B Domestic hot water tank fÖ Power supply connection, equipment (see page 60)
C Heating circuit with mixing valve 120 VAC aVH Connection of external
D Neutralizing unit fA Burner (1st stage) equipment (see page 60)
gS A1 Motorized isolation valve
lÖ Burner (2nd stage/modulating)
5351 338 v1.8

27
Heating system types

Circuit Diagram 11 (continued)

Possible applications The Vitocrossal 300 is operated with Motorized isolation valve
The cascade and DHW tank control constant boiler water temperature by Connect motorized isolation valve
must be activated by a building means of the boiler control unit. adaptor (Part No. 7134 560) or 24V
automation system. Two-stage or modulating burners can valve adaptor (Part No. 7134 559),
be controlled. installed in connection enclosure, in
parallel.
IMPORTANT The Vitocrossal 300 has two return Use electric junction box if necessary.
connections. The heating circuits
This circuit diagram represents a with the higher return temperature
recommendation only. It is the are connected to the return
responsibility of the customer and/or connection at the top, those with
heating contractor to check that this the lower temperatures to the return
recommendation is complete and fully connection at the bottom.
functional. Three-phase equipment
must be connected via additional Please note:
power contactors. At least 15% of the
take-off from the rated output must
be connected to the return connection
at the bottom.

The boiler water temperature which

is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0d: 2 Set coding ”0d: 0” –––
5351 338 v1.8

28
 Heating system types

Circuit Diagram 12

Multi-boiler system with several heating circuits, one mixing valve heating circuit and Vitorond with shunt pump
in conjunction with Vitocrossal 300 and Vitorond 200

C C

3
3 17B T2
17A
52 A1
143
146

143
146
41

41
40

90

40

90
29

T1

B D A A

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor gS A1 Motorized isolation valve
B Domestic hot water tank aJ A Temperature sensor T1 lÖ Burner (2nd stage/modulating)
C Heating circuit with mixing valve aJ B Temperature sensor T2 aVD Connection of external
D Neutralizing unit sL Shunt pump equipment (see page 60)
fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
fA Burner (1st stage)
5351 338 v1.8

29
Heating system types

Circuit Diagram 12 (continued)

Possible applications The Vitocrossal 300 (lead boiler) and The Vitocrossal 300 boilers have
The cascade and DHW tank control the Vitorond lag boilers are operated two return connections. The heating
must be activated by a building with modulating boiler water circuits with the higher return
automation system. temperature and load-dependent temperature are connected to the
sequential control by means of the return connection at the top, those
outdoor-reset logic control system. with the lower temperatures to the
IMPORTANT Two-stage or modulating burners can return connection at the bottom.
be controlled.
This circuit diagram represents a Through the control system which is Please note:
recommendation only. It is the linked via the LON BUS, the boiler At least 15% of the
responsibility of the customer and/or supply temperature which is take-off from the rated output must
heating contractor to check that this established is higher than the be connected to the return
recommendation is complete and fully maximum heating circuit supply connection at the bottom.
functional. Three-phase equipment temperature by an adjustable
must be connected via additional difference. The heating system can The return temperature raising
power contactors. be operated in accordance with a functionality of the Vitorond
separate heating curve. modulating boiler is available as an
accessory or must be provided on
site.
The return temperature is raised by
means of the shunt pump and by
closing the isolation valve.
The temperature sensor T1 activates
the isolation valve. The temperature
sensor T2 switches the shunt pump.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0C: 4 Only with Vitotronic 100 for the Vitocrossal –––
300:
Set coding ”0C: 0”
0d: 2 Set coding ”0d: 0” –––
4A: 0 ––– Only with Vitotronic 100 for the Vitorond:
Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Only with Vitotronic 100 for the Vitorond:
Connection of the temperature sensor T2 at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8

30
 Heating system types

Circuit Diagram 13

Multi-boiler system with return valve, several heating circuits and one mixing valve
heating circuit
in conjunction with Vitocrossal 300 and Vitorond 200

C C

3 3
17A
52 A1
143
146

143
146
41

41
40

90

40

90
29

T1

B D A A

A Boiler with Vitotronic 100, GC1 Plugs

B Domestic hot water tank § Boiler temperature sensor lÖ Burner (2nd stage/modulating)
C Heating circuit with mixing valve aJ A Temperature sensor T1 aVD Connection of external
D Neutralizing unit sL Boiler circuit pump equipment (see page 60)
fÖ Power supply connection, aVH Connection of external
120 VAC equipment (see page 60)
fA Burner (1st stage)
gS A1 3-port mixing valve
5351 338 v1.8

31
Heating system types

Circuit Diagram 13 (continued)

Possible applications The Vitocrossal 300 (lead boiler) and The Vitocrossal 300 boilers have
For heating circuits with temperature the Vitorond lag boilers are operated two return connections. The heating
differences ≥20 K. with modulating boiler water circuits with the higher return
The cascade and DHW tank control temperature and load-dependent temperature are connected to the
must be activated by a building sequential control by means of the return connection at the top, those
automation system. outdoor-reset logic control system. with the lower temperatures to the
Two-stage or modulating burners return connection at the bottom.
can be controlled.
IMPORTANT Through the control system which is Please note:
linked via the LON BUS, the boiler At least 15 % of the
This circuit diagram represents a supply temperature which is take-off from the rated output must
recommendation only. It is the established is higher than the be connected to the return connection
responsibility of the customer and/or maximum heating circuit supply at the bottom.
heating contractor to check that this temperature by an adjustable
recommendation is complete and fully difference. The heating system can The T1 temperature sensor measures
functional. Three-phase equipment be operated in accordance with a the return temperature.
must be connected via additional separate heating curve. The return valve is activated via the
power contactors. boiler control unit so as to ensure that
the return temperature does not fall
below the minimum value.

Available system accessories

Flue gas temperature sensor

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0C: 4 Only with Vitotronic 100 for the Vitocrossal –––
300:
Set coding ”0C: 0”
Only with Vitotronic 100 for the Vitorond
300: Set coding ”0C: 1” for continuous
return temperature control

0d: 2 Only with Vitotronic 100 for the Vitocrossal –––

300:
Set coding ”0d: 0”
4A: 0 ––– Only with Vitotronic 100 for the Vitorond:
Connection of the Therm-Control temperature
sensor at plug aJA;
Coding is automatically changed to ”4A: 1”
4d: 1 Only with Vitotronic 100 for the Vitocrossal
300:
5351 338 v1.8

Set coding ”4d: 2” for boiler circuit pump at

plug sL

32
 Heating system types

Circuit Diagram 14 (CM2 only)

Single-boiler system with several heating circuits and one mixing valve heating circuit
in conjunction with Vitocrossal 200

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor fÖ Power supply connection,
B Domestic hot water tank % DHW tank temperature sensor 120 VAC
C Heating circuit with mixing valve (accessory) fA Burner
D Mixing valve heating circuit sÖ A1 Close mixing valves with lÖ Burner modulation
or external heating circuit controls aVD Connection of external
E Underfloor heating circuit with sA DHW pump equipment (see page 60)
mixing valve aVH Connection of external
F Limit thermostat (max. limit) equipment (see page 60)
G Neutralizing unit
5351 338 v1.8

33
Heating system types

Circuit Diagram 14 (CM2 only) (continued)

Possible applications The Vitocrossal 200 is operated with

For heating circuits with different constant boiler water temperature by
temperatures. means of the boiler control unit and the
Viessmann fully modulating burner.

IMPORTANT
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional.

Coding of Change required Automatic change

system type
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: 2”
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0C: 4 Set coding ”0C: 0” –––
0d: 2 Set coding ”0d: 0” –––

5351 338 v1.8

34
 Heating system types

Circuit Diagram 15 (CM2 only)

Multi-boiler system with several heating circuits and one mixing valve heating circuit
in conjunction with Vitocrossal 200

Plugs
A Boiler with Vitotronic 100, GC1 § Boiler temperature sensor aVD Connection of external
B Domestic hot water tank fÖ Power supply connection, equipment (see page 60)
C Heating circuit with mixing valve 120 VAC aVH Connection of external
D Neutralizing unit fA Burner equipment (see page 60)
gS A1 Motorized isolation valve
lÖ Burner modulation
5351 338 v1.8

35
Heating system types

Circuit Diagram 15 (CM2 only) (continued)

Possible applications The Vitocrossal 200 is operated with Motorized isolation valve
The cascade and DHW tank control constant boiler water temperature by Connect motorized 120V isolation
must be activated by a building means of the boiler control unit and valve adaptor (Part No. 7511 367)
automation system. the Viessmann fully modulating burner. or 24V valve adaptor (Part No.
7511 366), installed in connection
enclosure, in parallel.
IMPORTANT Use electric junction box if necessary.

This circuit diagram represents a

recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional.

Coding of Change required Automatic change

system type
01: 1 Set coding ”01: 3” for multi-boiler system –––
with external cascade control via switch
contacts
02: 1 Set coding ”02: 2” for operation with –––
modulating burner
0d: 2 Set coding ”0d: 0” –––

5351 338 v1.8

36
 Installation

Mounting the Front Part of the Control Unit (VD2/VD2A/CT3 only)

1.

7.

8.

1. Position the front part of the housing

and clip hinges to counter-parts on
main housing.

2. Release the stay bar, open it up

and lock in position at point A. 6.
3. Insert the flat cable from the
Optolink into plug ”X20”.

4. Insert the plug of the programming

unit into socket ”X10”. Use cable
guides in cover for routing.

5. Engage the stay bar in the front

housing.
2.
6. Close the front of the housing. A

7. Secure front housing with supplied

screws.

8. Install cover of the connection

enclosure and support with supplied 5.
screw. 4.

3.
5351 338 v1.8

37
Installation

Opening the Control Unit (VD2/VD2A/CT3 only)

1. Remove the cover of the

connection enclosure.

2. 2. Unscrew the screws from the

front housing.

3. Swing up the front part of the

control housing.

4. Position the stay bar so that it

supports the front housing.

1.

3.

4. 5351 338 v1.8

38
 Installation

Control and Junction Box Installation Instructions (for CM2 only)

1. Route cables and capillaries from

control through the opening in the
control panel. Guide the cables to
the junction box through the
opening in the rear panel and along
the top rail to the control. Secure
all cables to the rail with cable ties.
Insert capillaries into the sensor well.
Note: Never allow cables to come
in contact with hot metal
components.

WARNING
Do not bend or kink the capillaries.
Damaging the capillaries leads to
malfunction.

2. Mount the control to the control

panel.

3. Secure the control to the control

panel with screws.
Note: Screws to secure control are
included with the cosmetic
cover in the boiler jacketing
package.

4. Install the junction box to the rear

panel either right or left. Secure the
junction box with 4 x 4.8 metal
screws.
Note:The ground screw and ground
wire can be removed and then
reinstalled with the boiler back
panel attached.
5351 338 v1.8

39
Installation

Mounting the Front Part of the Control Unit (CM2 only)

1. Position the front part of the housing

and clip hinges to counter-parts on
main housing.

2. Release the stay bar, open it up

and lock in position at point A.
A
3. Insert the flat cable from the
Optolink into plug ”X20”.

4. Insert the plug of the programming

unit into socket ”X10”. Use cable
guides in cover for routing.

5. Engage the stay bar in the front

housing.

6. Close the front of the housing.

7. Secure front housing with supplied

screws.

8. Install control cosmetic cover.

5351 338 v1.8

40
 Installation

Opening the Control Unit (CM2 only)

1. Remove the control cosmetic

cover .

2. Unscrew the screws from the

front housing.

3. Swing up the front part of the

control housing.

4. Position the stay bar so that it

supports the front housing.
5351 338 v1.8

41
Installation

Overview of Electrical Connections

145

17 B
17 A
5 151
3/2 90
15 21

143 52 A1/M1 41

146 20 A1/M1
29
50 150
40
156
156

Low voltage connections (motherboard) Line voltage connections (motherboard)

§ Boiler temperature sensor (KTS) sÖ A1Control output
% DHW tank temperature sensor sA DHW pump
aG Flue gas temperature sensor sL Shunt pump or
aJA Return temperature sensor T1 boiler circuit pump
aJB Return temperature sensor T2 fÖ Power supply connection
aVD Connection of external fA Burner (1st stage)
equipment gÖ Compiled failure alarm
aVG KM BUS participant gS A1Return valve
aVH Connection of external or
equipment Isolation/modulating valve
lÖ Burner (2nd stage/modulating)
aBÖ Connection of external
equipment, e.g. additional
5351 338 v1.8

safety equipment
aBA Safety circuit, potential free
aBH Power supply connection for
accessories

42
 Installation

Overview of Electrical Connections (VD2/VD2A/CT3 only) (continued)

[29]
[20] A1
5351 338 v1.8

43
Installation

Overview of Electrical Connections (CM2 only) (continued)

5351 338 v1.8

44
 Installation

Routing and Strain Relief of Cables

1. Run the cables from the connection enclosure into the control unit.
2. Apply strain relief to cables (see below).

Cables with moulded strain relief

clamp

Connect cable and strain relief clamp.

OR

Fasten cable to the cable lead with

cable tie.
5351 338 v1.8

45
Installation

Inserting the Boiler Coding Card

CAUTION
For matching the operation of the
control unit to the boiler, the boiler
coding card which is supplied as part
of the standard delivery of the boiler
may be used.

Only use the boiler coding card included with the boiler.

Boiler Coding card Part no.

Vitocrossal 300, type CT3 1040 7820 144
Vitorond 200, VD2 / VD2A 1020 7820 142
Vitocrossal 200, CM2 1041 7820 145

1. Push the boiler coding card through

the recess in the cover and insert
it in plug-in location ”X7”.

5351 338 v1.8

46
 Installation

Setting of the Fixed High Limit (if required)

Settings on the control unit

The setting for the fixed high limit and A
the other settings are dependent on the The fixed high limit is supplied with
safety equipment installed in a factory setting of 110°C / 230°F.
accordance with applicable codes.

- On Vitotronic 100, GC1 for

Vitorond 200, VD2 of
110°C / 230°F
- Adjustment to 99°C / 210°F

- On Vitotronic 100, GC1 for

Vitocrossal 300, CT3
Vitocrossal 200, CM2
of 99°C / 210°F
3. No adjustment

¨ Disconnect power to control and

burner!

1. Unclip the fuse box and swing

upwards.

2. Turn the slotted screw on the rear

of the fixed high limit until the slot
points to 99°C / 210°F (once
1. adjusted, the fixed high limit cannot
be reset to 110°C / 230°F).

3. Re-fit the fuse box.

2.

Non-condensing boiler Condensing boiler Condensing boiler

(VD2/VD2A) °C / °F (CT3) °C / °F (CM2) °C / °F
Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210
Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203
Coding for the electronic maximum 93 / 200 87 / 188 87 / 188 88 / 190
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less
5351 338 v1.8

47
Installation

Setting of the Adjustable High Limit (if required)

The adjustable high limit is supplied

with a factory setting of 95°C / 203°F
Adjustment to 100°C / 212°F

1. Disconnect power to control and

burner.

A 2. Using a suitable screwdriver,

lever out and remove the selector
knob ”R” behind the hinged cover.

3. Using a pair of pointed pliers, break

off the cams identified by the
shaded areas in the Fig. from the
3. stop dial.

A 75 to 1100°C
2. 167 to 212°F

4. Fit the selector knob ”R” so that

the marking is in the centre of the
selected range.

IMPORTANT
Note the setting of coding address
”06”!

WARNING
If the system is operated in
conjunction with a domestic hot
water tank, ensure that the
maximum permissible domestic
hot water temperature is not
exceeded. If necessary, install a
suitable safety device for this
purpose.

1. 5351 338 v1.8

48
 Installation

Sensor Connection

17B 17A 3 15

1 2 3 1 2 3 1 2 3 1 2 3

A B C D

ATemperature sensor T2
BTemperature sensor T1
CBoiler temperature sensor
DFlue gas temperature sensor
5351 338 v1.8

49
Installation

Connection of the Boiler Temperature Sensor

Electrical connection
See page 42.

3 The sensor measures the boiler

water temperature of the boiler.

The boiler temperature sensor is

installed at the same time as the
boiler insulation.

Check the sensor

1. Disconnect plug § in the
terminal compartment.

2. Measure resistance of sensor at

terminals ”1” and ”2” of the plug
or ”2” and ”3” (if a second DHW
tank temperature sensor is
connected).

Boiler water Resistance

temperature in Ω
in °C / °F
40 / 104 578
50 / 122 597
760 60 / 140 616

740 3. Compare the value measured with

the current temperature. If the
value differs significantly, check
720
installation and, if necessary,
replace sensor.
700
Technical data
680 Degree of protection: IP 32
Ambient temperature
during operation:
660 0 to + 130°C
32 to + 266°F
640 during storage and transport:
-20 to + 170°C
- 4 to + 158°F
620

600 Electrical connection

The sensors are ready to plug in.
Insert the boiler temperature sensor
580
in socket ”3” of the boiler control.
Resistance in

560

400
540
0 20 40 60 80 100 120 140
5351 338 v1.8

32 68 104 141 176 212 248 284

Boiler temperature in °C / °F

50
 Installation

Connection of the DHW Tank Temperature Sensor

The sensor measures the domestic hot Heating systems with domestic hot Electrical connection
water tank temperature. water heating (single-boiler systems See page 42.
only)
The sensor measures the boiler
1. Install the DHW tank temperature water temperature of the boiler.
sensor.
5 The boiler temperature sensor is
See installation instructions installed at the same time as the
for domestic hot water tank boiler insulation.

Please note: Check the sensor

When installing the sensor in DHW 1. Disconnect plug % in the
tanks of other makes, make sure terminal compartment.
that the sensor is pressed against
the sensor well of the DHW tank by 2. Measure resistance of sensor at
means of a suitable device. terminals ”1” and ”2” of the plug
or ”2” and ”3” (if a second DHW
tank temperature sensor is
2. Ensure that the maximum connected).
permissible domestic hot water
temperature is not exceeded. If DHW tank Resistance
necessary, install a suitable safety temperature in Ω
device for this purpose. in °C / °F
Heating systems without domestic hot 40 / 104 578
water heating 50 / 122 597
60 / 140 616
Do not connect the DHW tank
temperature sensor. 3. Compare the value measured with
760 the current temperature. If the
value differs significantly, check
740 installation and, if necessary,
replace sensor.
720
Technical data
Degree of protection: IP 32
700 Ambient temperature
during operation:
680 0 to + 130°C
32 to + 266°F
during storage and transport:
660 -20 to + 170°C
- 4 to + 158°F
640

Electrical connection
620 The sensors are ready to plug in.
Insert the DHW temperature sensor
600 in socket ”5” of the boiler control.

580
Resistance in

560
5351 338 v1.8

400
540
0 20 40 60 80 100 120 140
32 68 104 141 176 212 248 284
DHW temperature in °C / °F

51
Installation

Connection of the Return Temperature Sensor

Strap-on temperature sensor and immersion temperature sensor

For measuring the boiler return
and return temperature.

Electrical connection
17A or 17B The sensor is inserted in socket
”17A” or ”17B” on the boiler
control.

Check the sensor

1. Disconnect plug aJA or aJB
in the terminal compartment of
the boiler control.

2. Measure resistance of sensor at

terminals ”1” and ”2” of the plug.

Return Resistance
temperature in Ω
in °C / °F
17A or 17B 30 / 86 569
40 / 104 592
60 / 140 643

3. Compare the value measured with

the current temperature. If the
740 value differs significantly, check
installation and, if necessary,
720 replace sensor.

Technical data
700 Degree of protection: IP 32
Ambient temperature
680 during operation: 0 to + 100°C
32 to + 212°F
during storage and transport:
660 -20 to + 70°C
-4 to + 158°F
640

620

600

580
Resistance in

560

540
5351 338 v1.8

20 30 40 50 60 70 80 90 100
68 86 104 122 140 158 176 194 212
Return temperature in °C / °F

52
 Installation

Connection of the Flue Gas Temperature Sensor (VD2/VD2A/CT3 only)

The sensor measures the flue gas

temperature and monitors the
selected limit value.

Electrical connection
The sensor is inserted in socket
”15” on the control unit.

Check flue gas temperature sensor

1. Disconnect plug aG in the
terminal compartment.

2. Measure resistance of sensor at

terminals ”1” and ”2” of the
plug.

Flue gas Resistance

temperature in Ω
in °C / °F
180 / 176 650
1020 160 / 320 800
200 / 392 880
980
3. Compare the value measured
940 with the current temperature.
If the value differs significantly,
check installation and, if
900
necessary, replace sensor.

860 Technical data

Degree of protection: IP 60
820 Ambient
temperature
during operation:
780
0 to + 600°C
32 to + 1112°F
740 during storage and transport:
–20 to + 670°C
700 - 4 to + 158°F

660

620
Resistance in Ω

580

540

500
0 40 80 120 160 200 240 280
32 104 176 248 360 392 464 536
5351 338 v1.8

Flue gas temperature in °C / °F

53
Installation

Connection of the Pumps (VD2/VD2A/CT3 only)

Available pump connections

20A1/M1

29

sÖ A1/M1Heating circuit high 120 VAC pumps 240 VAC or 3 PH pumps

temperature (without mixing valve)
Terminals 5 - L, - G , - N Note: Please note:
The maximum power consumption of Use contactor and/or motor starter to
sA Circulation pump for heating all pumps is 4A . power pump.
up the domestic hot water tank - Rated current: max. 2 FLA For activating the contactor:
Terminals 4 - L, - G , - N Recommended connection Rated current: max. 2 FLA
cable: AWG 14 Recommended connection
sL Shunt pump, boiler circuit pump wire size: AWG 14
Terminals 6 - L, - G, - N. Use contactor for pumps with higher
current rating Please ensure that all connections and
Install pumps: see wire sizes comply with local and
manufacturer’s Connect the 3-wire cable from the national codes.
instructions. pump to the corresponding terminals.
1.Select the contactor and the
connecting wire in accordance with
the rating of the pump that is to be
connected.

2.Connect pump and power supply to

the contactor.

3.Connect contactor coil to the

corresponding terminals.
5351 338 v1.8

54
 Installation

Connection of the Pumps (CM2 only)

Available pump connections

sÖ A1/M1Heating circuit high 120 VAC pumps 240 VAC or 3 PH pumps

temperature (without mixing valve)
Terminals 7 - L, - G , - N Note: Please note:
The maximum power consumption Use contactor and/or motor starter
sA Circulation pump for heating of all pumps is 4A . to power pump.
up the domestic hot water tank - Rated current: max. 2 FLA For activating the contactor:
Terminals 6 - L, - G , - N Recommended connection Rated current: max. 2 FLA
cable: AWG 14 Recommended connection
sL Shunt pump, boiler circuit pump wire size: AWG 14
Terminals 8 - L, - G, - N. Use contactor for pumps with higher
current rating Please ensure that all connections
Install pumps: see and wire sizes comply with local and
manufacturer’s Connect the 3-wire cable from the national codes.
instructions. pump to the corresponding terminals.
1.Select the contactor and the
connecting wire in accordance
with the rating of the pump that
is to be connected.

2.Connect pump and power supply

to the contactor.

3.Connect contactor coil to the

5351 338 v1.8

corresponding terminals.

55
Installation

Connection of Boiler Return Mixing Valve or Isolation/Modulating Valve

actuator
(VD2/VD2A/CT3 only)

1 120V or 24V Valve Adaptor 1 120V Valve Adaptor 1 24V Valve Adaptor

2 DIN rail in connection enclosure 2 120V valve actuator 2 24V valve actuator

3 aBH Terminals

120V Valve Adaptor 1. Disconnect power to control.

Rated voltage: 120 VAC
Rated current: max. 0.1 FLA 2. Install 120V or 24V Valve
Recommended connection Adaptor on DIN rail inside
wire size: AWG 14 connection enclosure.
Part No. 7134 560
3. Insert the plug gS into socket
24V Valve Adaptor gS on the control.
Rated voltage: 24 VAC
Rated current: max. 0.15 FLA 4. Fasten cable with tie
Recommended connection (see page.45).
wire size: AWG 14
Part No. 7134 559 5. Connect black wire of the
adaptor to connection aBH on
Operating time: the DIN rail
5 to 199 sec. selected via coding - Terminal 8,9 or 10.
address “40”.
6. Connect valve actuator wires
to the adaptor terminals as
shown on figures.
5351 338 v1.8

56
 Installation

Connection of Boiler Return Mixing Valve or Isolation/Modulating Valve

actuator
(CM2 only)

10 11 12

1 120V or 24V Valve Adaptor 1 120V Valve Adaptor 1 24V Valve Adaptor

2 DIN rail in connection enclosure 2 120V valve actuator 2 24V valve actuator

3 120V L out power supply

120V Valve Adaptor 1. Disconnect power to control.

Rated voltage: 120 VAC
Rated current: max. 0.1 FLA 2. Install 120V or 24V Valve
Recommended connection Adaptor on DIN rail inside
wire size: AWG 14 connection enclosure.
Part No. 7511367
3. Insert the plug gS into socket
24V Valve Adaptor gS on the control.
Rated voltage: 24 VAC
Rated current: max. 0.15 FLA 4. Fasten cable with tie
Recommended connection (see page.45).
wire size: AWG 14
Part No. 7511366 5. Connect black wire of the
adaptor to connection 120V L
Operating time: out the DIN rail
5 to 199 sec. selected via coding - Terminals 10,11 or 12.
address “40”.
6. Connect valve actuator wires
to the adaptor terminals as
shown on figures.
5351 338 v1.8

57
Installation

Making Space for Accessory Adaptors on the DIN Rail (CM2 only)

1. Push up on the bottom front of

the DIN rail clamp to remove and
set aside.

2. Using a flat head screwdriver,

remove the 4 ’spare’ DIN
terminals 23, 24, 25 and 26 one
at a time. Place the screwdriver
between the rail and the base of
the terminal and turn the
screwdriver clockwise . Discard
the removed terminals.

3. Re-install the DIN rail clamp by

hooking the latch of the clamp
around the top of the rail and then
push down on the front of the
clamp.

Note: See separate Installation

Instructions for accessory
adaptors.

5351 338 v1.8

58
 Installation

Vitotronic 100, GC1 with 30% LTP Package (VD2/VD2A only)

1 - 17B Sensor (strap-on)

5351 338 v1.8

VD2/VD2A

59
Installation

Connection of External Controls

Operation with two-stage burner

Dry contacts of the building automation

A system:

1st stage burner ON

B
2nd stage burner ON

C External changeover of
staged/modulating burners

D Boiler activation, isolation valve open

or closed (on multi-boiler system only)

B D
Switch on 2nd stage burner Boiler activation, isolation valve
Connect dry contact at terminals ”2” open or closed
and ”3” Connect dry contact at terminals ”2”
143 146 of the plug aVD. and ”3” of the plug aVH.

Contact closed: Contact closed:

Both burner stages are switched on. First, the preheat function for
The boiler water temperature is limited follow-up boilers is activated
A by the electronic maximum (coding address ”2b”).
Switch on 1st stage burner temperature limit (coding address ”06”) When the preheat function finishes,
Connect dry contact at terminals ”1” if this is set below the value preset on the minimum temperature is
and ”2” of the plug aVD . the mechanical adjustable high limit maintained for the boiler (not with
”R”. Vitocrossal 300), and the burner
Contact closed: The 2nd stage burner is switched off stages can be switched externally.
The 1st stage burner is switched on. 2 K sooner. The boiler water temperature is
The 2nd stage burner is only switched limited by the preset electronic
on to maintain the minimum Contact open: maximum temperature limit or via
The 1st and 2nd stage burner are the mechanical adjustable high limit.
temperature (not with Vitocrossal
switched off. The setpoint value is selected via
300). The boiler water temperature is
the coding address ”9b”.
limited by the electronic maximum
temperature limit (coding address ”06”)
C Contact open:
if this is set below the value preset on External changeover of The isolation valve is closed after
the mechanical adjustable high limit staged/modulating burners approximately. 5 minutes
”R”. Connect dry contact at terminals ”1” (coding address ”2C”).
and ”2” of the plug aVH. External override of the burner stages
Contact open: is not possible, and no minimum
The 1st stage burner is switched off. Contact closed: temperature is maintained.
Modulating operation.

Contact open:
Two-stage operation. Coding “02: 2”
(modulating burner) must be set.
5351 338 v1.8

Note:
Even if contact is closed, scanning the
type of burner will continue to display
“modulating”.

60
 Installation

Connection of External Controls (continued)

Operation with two-stage burner

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler Condensing boiler Condensing boiler

(VD2/VD2A) °C / °F (CT3) °C / °F (CM2) °C / °F
Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210
Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203
Coding for the electronic maximum 93 / 200 87 / 188 87 / 188 88 / 190
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

Single-boiler systems: Multi-boiler systems:

Coding ”01: 1” Set coding ”01: 3”
(factory setting)

When a building automation system is When a building automation system

connected, only the connections on is connected, the connections on
plug aVD are required. The DHW tank plugs aVD and aVH are required. The
control unit is activated when the DHW DHW tank temperature and the
tank temperature sensor is connected. load-dependent cascade control must
The boiler water temperature must be be controlled through the bulding
set to the minimum value. automation system.

CAUTION
The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler must
be constantly closed.
5351 338 v1.8

61
Installation

Connection of External Controls (VD2/VD2A only) (continued)

Modulating boilers – operation with external modulation controller (continued)

1st stage burner fA from Boiler activation, isolation valve open

Vitotronic 100. or closed
Connect dry contact at terminals ”2”
Plug lÖ from Vitotronic 100 via and ”3” of the plug aVH.
modulation controller (BAS).
Contact closed:
On the building automation unit with First, the preheat function for follow-
modulation controller set the minimum up boilers is activated (coding
temperatures 5°C / 9°F above the address ”2b”).
minimum boiler water temperature of When the preheat function finishes,
the boiler. the minimum temperature is
maintained for the boiler, and the
burner stages/modulation can be
switched externally.
The boiler water temperature is
limited by the preset maximum
boiler water temperature or via the
mechanical adjustable high limit.
The set-point value is selected via
the coding address ”9b”.

Contact open:
The isolation valve is closed after
approx. 5 minutes (coding address
”2C”).
External override of the burner stages
is not possible, and no minimum
temperature is maintained.

Switch on 1st stage burner (basic

load)
Connect dry contact at terminals ”1”
and ”2” of the plug aVD.

Contact closed:
The 1st stage burner is switched on.
The full load is only switched on to
maintain the minimum temperature
(not with Vitocrossal 300). The
boiler water temperature is limited
by the electronic maximum
temperature limit (coding address
”06”) if this is set below the value
preset on the mechanical adjustable
high limit ”R”.

Contact open:
The 1st stage burner is switched off.
5351 338 v1.8

62
 Installation

Connection of External Controls (VD2/VD2A only) (continued)

Modulating boilers – operation with external modulation controller

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler Condensing boiler Condensing boiler

(VD2/VD2A) °C / °F (CT3) °C / °F (CM2) °C / °F
Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210
Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203
Coding for the electronic maximum 93 / 200 87 / 188 87 / 188 88 / 190
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

Single-boiler systems: Multi-boiler systems:

Coding ”01: 1” Set coding ”01: 3”
(factory setting)

When a building automation system is When a building automation system

connected, only the connections on is connected, the connections on
plug aVD are required. The DHW tank plugs aVD and aVH are required. The
control unit is activated when the DHW DHW tank temperature and the
tank temperature sensor is connected. load-dependent cascade control
The boiler water temperature must be must be controlled through the
set to the minimum value. external building automation system.

CAUTION
The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler must
be constantly closed.
5351 338 v1.8

63
Installation

Connection of External Controls (CT3 only) (continued)

Vitocrossal 300 – operation with external modulation controller

1st stage burner fA from Boiler activation, isolation valve open

Vitotronic 100. or closed
Connect dry contact at terminals ”2”
Connection lÖ from Vitotronic 100 and ”3” of the plug aVH.
has no function.
Contact closed:
Connection lÖ from building First, the preheat function for
automation system to the burner. follow-up boilers is activated
(coding address ”2b”).
1st stage burner activated by the When the preheat function finishes,
modulation controller via connection the burner stages/modulation can be
aVH. switched externally.
The boiler water temperature is
limited by the preset maximum boiler
water temperature or via the
mechanical adjustable high limit.
The set-point value is selected via the
coding address ”9b”.

Contact open:
The isolation valve is closed after
approximately 5 minutes (coding
address ”2C”).
External override of the burner
stages is not possible, and no
minimum temperature is maintained.

Switch on 1st stage burner (basic

load)
Connect dry contact at terminals ”1”
and ”2” of the plug aVD.

Contact closed:
The 1st stage burner is switched on.
The boiler water temperature is
limited by the electronic maximum
temperature limit (coding address
”06”) if this is set below the value
preset on the mechanical adjustable
high limit ”R”.

Contact open:
The 1st stage burner is switched off.
5351 338 v1.8

64
 Installation

Connection of External Controls (CT3 only) (continued)

Vitocrossal 300 – operation with external modulation controller (continued)

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler Condensing boiler Condensing boiler

(VD2/VD2A) °C / °F (CT3) °C / °F (CM2) °C / °F
Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210
Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203
Coding for the electronic maximum 93 / 200 87 / 188 87 / 188 88 / 190
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

Single-boiler systems: Multi-boiler systems:

Coding ”01: 1” Set coding ”01: 3”
(factory setting)

When a building automation system is When a building automation system

connected, only the connections on is connected, the connections on
plug aVD are required. The DHW tank plugs aVD and aVH are required. The
control unit is activated when the DHW DHW tank temperature and the
tank temperature sensor is connected. load-dependent cascade control must
The boiler water temperature must be be controlled through the building
set to the minimum value. automation system.

CAUTION
The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler must
be constantly closed.
5351 338 v1.8

65
Installation

Connection of Combustion Air Device (VD2/VD2A/CT3 only)

Connection of the Combustion Air

Device Adaptor

1. Disconnect power to control and

burners.
2. Install Combustion Air Device
Adaptor,
Part No. 7134 563
on DIN Rail inside connection
enclosure (refer to installation
manual of Combustion Air Device
Adaptor).
3. Remove jumper between terminals
16 and 17.
4. Make connection as shown in the
diagram.

IMPORTANT
Wire BK2 must be connected to
terminal 16 and BK3 to terminal 17 -
DO NOT reverse.

A Combustion Air Device Adaptor

B DIN Rail in connection enclosure

Connection of the combustion air

blower to adaptor

Rated voltage: 120 VAC

Rating current: max 5 FLA
Recommended connection
wire size: AWG 14

Ensure that combustion air blower

device is suitable for this application.

For detailed instruction on adaptor

installation please refer to the adaptor’s
installation manual.

1. Make connection as shown in the

D diagram at left.

A Combustion Air Device Adaptor in

connection enclosure
B Combustion air blower motor
C Proving switch - “normally open”
rated for 120 VAC.
D Power supply, 120 VAC

¨ Safety instruction!
5351 338 v1.8

Provide disconnect means and

overcurrent protection as required by
local codes.

66
 Installation

Connection of Combustion Air Device (CM2 only)

Connection of the Combustion Air Connection of the combustion air

Device Adaptor blower to adaptor

1. Disconnect power to control and Rated voltage: 120 VAC

burners. Rating current: max 5 FLA
Recommended connection
2. Install Combustion Air Device wire size: AWG 14
Adaptor, Part No. 7134 563
on DIN Rail inside the boiler junction Ensure that combustion air blower
box (refer to installation manual of device is suitable for this application.
Combustion Air Device
Adaptor). For detailed instruction on adaptor
installation please refer to the
3. Remove plug 150 from Vitotronic adaptor’s installation manual.
control. Remove jumper between
the 2 ’TR’ terminals. Using 14 AWG 1. Make connection as shown in the
(field supplied) connect plug diagram at left.
D terminals TR(Left), TR(Right) and
neutral to the DIN rail. A Combustion Air Device Adaptor
in connection enclosure
Neutral to Terminal 16 B Combustion air blower motor
TR(Left) to Terminal 18 C Proving switch - “normally open”
TR(Right) to Terminal 19 rated for 120 VAC.
D Power supply, 120 VAC
Re-install the 150 plug and DIN rail
connections as shown in the diagram. ¨ Safety instruction!
Provide disconnect means and
overcurrent protection as required
IMPORTANT by local codes.

Wire BK2 must be connected to

terminal 18 and BK3 to terminal 19 -
DO NOT reverse.
5351 338 v1.8

67
Installation

Connection of Combustion Air Device (continued)

Connection of the combustion air

damper

See damper manual for correct

installation.

Ensure that the combustion air

damper is suitable for this application.

E
1. Disconnect power to control and
burner.

2. Make connection as shown in the

diagram.

A Combustion Air Device Adaptor

in connection enclosure
B Relay 120 VAC coil - field supplied
C Combustion air damper
D End switch rated for 120 VAC
wired to “normally open” terminal
on device adaptor board
E Power supply, 120 VAC

¨ Safety instruction!
Provide disconnect means and
overcurrent protection as required by
local codes.

Note:
Spring return air dampers do not
require field supplied relay.

5351 338 v1.8

68
 Installation

Connection of Combustion Air Device on Multiple Boiler Systems

If a single combustion air device is

required for a multiple boiler system, a
Common Combustion Air Interface
must be installed.

Rated voltage: 120 VAC

Rating current: max 5 FLA
Recommended connection
wire size: AWG 14

1. Install Combustion Air Device

Adaptor on each boiler.
Part No. 7134 563

2. Install Common Combustion Air

Device Interface,
Part No. 7134 604
as per supplied manual.

3. Make connection as shown in the

diagram at left.

A Common Combustion Air Device

Interface (wall mount)
B Combustion Air Device Adaptor
in connection enclosure on each
boiler
C Interconnecting wiring
(field supplied and connected)

Refer to Istallation and Operating

Instructions of Common Combustion
Air Device Interface for details.
5351 338 v1.8

69
Installation

Connection of Single Combustion Air Device on Multiple Boiler Systems

Connection of the combustion air

blower

A Common Combustion Air Device

Interface
B Combustion air device motor
120VAC, 5 FLA max.
C Proving switch rated for 120 VAC
D Power supply, 120 VAC

¨ Safety instruction!
Provide disconnect means and
overcurrent protection as required
by local codes.

See blower manual for current

rating to correctly select the fuse.

See Common Combustion Air

D Device Interface manual for
Installation and Operating details.

1. Disconnect power to control and

burner.

2. Make the connections as shown

in the diagram.

5351 338 v1.8

70
 Installation

Connection of Combustion Air Damper

Connection of the combustion air

damper

A Common Combustion Air Device

Interface
B Combustion air device motor
120VAC, 5 FLA max
C Proving switch rated for 120 VAC
D Power supply, 120 VAC

¨ Safety instruction!
Provide disconnect means and
overcurrent protection as required
by local codes.

See damper manual for current

rating to correctly select the fuse.

See Common Combustion Air

Device Interface manual for
Installation and Operating details.

1. Disconnect power to control and

burner.

2. Make the connections as shown

in the diagram.
5351 338 v1.8

71
Installation

Flue Gas Temp. Switch (mandatory for PP(s) material collectors)

(CM2 only)
1. Disconnect power.

CAUTION 2. Remove 150 plug from the

Please note that the diagram shown Vitotronic control and discard.
is only a simplified conceptual
drawing of a flue gas temperature 3. Install new 150 plug supplied
switch. Refer to the manual specific (attached to flue gas temperature
to the device for interconnection switch).
details.

5351 338 v1.8

72
 Installation

Connection of Low Water Cut-off Device (VD2/VD2A/CT3 only)

1. Remove jumper between terminals

12 and 15.

2. Make connection as shown in

diagram.

CAUTION
Please note that the diagram at left
is only a simplified conceptual
drawing of a typical low water
cut-off (LWCO) device. Refer to the
manual specific to the device for
interconnection details.

aBH Power supply for accessories.

aBÖ Connection for external

equipment.
5351 338 v1.8

73
Installation

Connection of Low Water Cut-off Device (CM2 only)

1. Remove jumper between terminals

21 and 22.

2. Make connection as shown in

diagram.

CAUTION
Please note that the diagram shown
is only a simplified conceptual
drawing of a typical low water
cut-off (LWCO) device. Refer to the
manual specific to the device for
interconnection details.

5351 338 v1.8

74
 Installation

Connections to Terminal aBÖ (VD2/VD2A/CT3 only)

External shut-off
1. Remove jumper between terminals
16 and 17.
2. Connect dry contact.
Controlled switch-off takes place
when the contact is opened.

CAUTION
The terminals should be used for
safety switch-off purposes only (e.g.
through a limit thermostat). See
pages 52 to 59 for details of
controlled switch-off.
During switch-off, there is no frost
WARNING
protection of the heating system and
the boiler is not kept at the minimum
boiler water temperature.

Emergency operation
Move jumper from terminals 16 and 17
to terminals 17 and 18.
A Jumper
B External shut-off (dry contact)
5351 338 v1.8

75
Installation

Connection of the Compiled Failure Alarm Indicator (VD2/VD2A/CT3 only)

Rated voltage: 120 VAC 60 Hz

Rated current: max. 2 FLA
A Recommended connection
wire size: AWG 14

1. Disconnect power to control and

burner.

2. Connect the compiled failure alarm

as shown in the diagram.

A Connect terminal strip in

connection enclosure of boiler
control

B Visual and/or audible alarm

device (120 VAC)

5351 338 v1.8

76
 Installation

Connection of the Compiled Failure Alarm Indicator (CM2 only)

Rated voltage: 120 VAC 60 Hz

9 Rated current: max. 2 FLA
A Recommended connection
wire size: AWG 14

1. Disconnect power to control and

burner.

2. Connect the compiled failure alarm

as shown in the diagram.

A Connect terminal strip in

connection enclosure of boiler
control

B Visual and/or audible alarm

device (120 VAC)

B
5351 338 v1.8

77
Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only)

For burners with plug-in connection

A The burner cables are included in the

standard delivery of the Vitotronic.
Connect the burner in accordance with
applicable codes.

ATo boiler control unit 1.Disconnect power to burner and

BTo burner boiler control.

Terminal codes 2. Connect plugs fA and plug lÖ to

respective counter plugs in boiler
L1 Phase via fixed high limit to the control unit.
burner
? Ground connection 3. Connect the 7-pole plug fA and the
N Neutral connection to the burner 3-pole plug lÖ to the burner.
T1,T2 Control circuit
S3 Connection for burner fault
indicator
41 B4 Connection for burner hours
120 VAC counter

A To plug-in connection in connection Terminal codes

enclosure
B To burner 1,2,3 Control circuit ”2nd stage
burner or modulation controller”
(via two-point controller with
2-stage operation;
via three-point controller with
modulating operation)
1 From burner
2 Modulating down
3 Modulating up/2nd stage ON

Colour codes as applicable

BK Black
BN Brown
5351 338 v1.8

BU Blue

78
 Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only) (continued)

CAUTION
This is a generic connection drawing
only! Follow the burner
manufacturer’s connection drawings
for Viessmann controls.

Write the terminal numbers or

markings on the drawing for future
reference.

Plug connection
located on the
DIN rail. See page
42 for details.

a b

Burner power supply not shown.

A Control unit fÖ Power supply connection of control aBÖ Plugs for external equipment
(Legend: see wiring diagram) unit 120 VAC a External safety devices
B 2nd stage or modulating *1 fA Burner, 1st stage (remove jumper when connecting)
C Hours counter, stage 1 *1 lÖ Burner, 2nd stage b External controlled switch-off
D Burner fault indicator *1 (remove jumper when connecting)
E Control circuit, stage 1/ aBA Safety circuit. Emergency
5351 338 v1.8

basic load *1 shut-off

F Burner

*1 Refer to burner manufacturer’s instruction on detailed connections for Viessmann controls.

79
Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only) (continued)

Burner motor power supply connection

(continued)
See burner manual for correct fuse
For burners with 240 VAC, 1PH power and wire gauge sizing, and specific
supply and connection in conduit. connections for Viessmann controls.

1.Disconnect power to burner and

boiler control.

2.Connect 240 VAC power to the

terminals 21, 22 and 23 on the
DIN rail inside the connection
enclosure. Provide fuseable
disconnect means according to
local codes.

3.Connect supplied power cable to

the motor terminals on the burner.

4.Connect cable plug to the socket

on the DIN rail in the connection
enclosure.

A Burner motor power supply

240 VAC, 1PH
B Connection terminals and plug
inside connection enclosure
C Cable and conduit- factory supplied
D Burner
E Motor starter
F Burner motor
G Connection enclosure on boiler
control
5351 338 v1.8

80
 Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only) (continued)

Burner motor power supply connection

(continued) See burner manual for correct fuse
and wire gauge sizing, and specific
For burners with 3PH 208, 460 or connections for Viessmann controls.
575V power supply.
1.Disconnect power to burner and
boiler control.

2.Connect 3PH power to the

terminals 21, 22, 23 and 24 on
the DIN rail inside the connection
enclosure. Provide fuseable
disconnect means according to
local codes.

3.Connect supplied power cable to

the motor terminals on the burner.

4.Connect cable plug to the socket

on the DIN rail in the connection
enclosure.

CAUTION
During commissioning check for
correct motor rotation. If motor
rotates in opposite direction than
indicated on the burner, disconnect
power supply and reverse wires BK1
and BK2 on the burner terminals.

A Burner motor power supply 3PH

208, 460 or 575V
B Connection terminals and plug
inside connection enclosure
C Cable and conduit - factory
supplied
D Burner
E Motor starter
F Overload
G Burner motor
H Connection enclosure
5351 338 v1.8

81
Installation

Power Supply Connection, Boiler Control (VD2/VD2A/CT3 only)

Legend 1. Ensure that the main power supply

L: Line to the control contains overcurrent
N: Neutral protection with a maximum rating
G: Ground of 15 A and 2 pole disconnect.
A Power supply 120 VAC, 1 PH .
Provide disconnect means and
overcurrent protection as per local CAUTION
codes The control must be grounded.
B Terminals [40] Ensure that “L”, “N” and “G” are not
C Connection enclosure interchanged.

2. Connect power supply wire to the

Connection fÖ terminals 11, N and
G on the DIN rail inside the
connection enclosure.

5351 338 v1.8

82
 Installation

Burner Connection, Burner Control Wiring (CM2 only)

For burners with plug-in connection

A The burner cables are included in the

standard delivery of the Vitotronic.
Connect the burner in accordance with
applicable codes.

ATo boiler control unit 1.Disconnect power to burner and

BTo burner interface boiler control.

Terminal codes 2. Connect plugs fA and plug lÖ to

respective counter plugs in boiler
L1 Phase via fixed high limit to the control unit.
burner
? Ground connection 3. Connect the 7-pole plug fA and
N Neutral connection to the burner the 3-pole plug lÖ to the burner.
T1,T2 Control circuit
S3 Connection for burner fault
indicator
B4 Connection for burner hours
counter

A
A To plug-in connection in connection Terminal codes
enclosure
B To burner interface 1,2,3 Control circuit ”2nd stage
burner or modulation controller”
(via two-point controller with
2-stage operation;
via three-point controller with
modulating operation)
1 From burner
2 Modulating down
3 Modulating up/2nd stage ON

Colour codes as applicable

BK Black
BN Brown
5351 338 v1.8

BU Blue

83
Start-up

Procedure (overview)

Page

1. Controls and indicators .............................................................................. 85

2. Check the fixed high limit ..................................................................... 86

3. Integrate the control unit in the LON BUS system

(in conjunction with heating circuits connected downstream) ....... 87

4. Carry out participant check ................................................................... 88

5. Match the control unit to the system type ..................................... 89

6. Check outputs (actuators) and sensors ........................................... 89

7. Match the coding addresses ................................................................. 90

5351 338 v1.8

84
 Start-up

Steps

1. Controls and indicators

Override switch

Boiler water temperature

(without function on multi-boiler
systems)

Domestic hot water temperature

(without function on multi-boiler
systems)

Value selection buttons

Information

Confirmation

Basic setting

Display window

Heating program selector buttons

(w without function on multi-boiler
systems)

Adjustable high limit

Fixed high limit reset button

F1 T6,3 A

TUV

F2 T6,3 A

Control on/off switch

Fuses

TUV button

Operating status indicator (green)

5351 338 v1.8

Fault indicator (red)

85
Start-up

Steps (continued)

2. Check the fixed high limit

The check is made via the ”TUV button” (see page 85).

When making the check, the ”TUV”

button must be kept continuously
pressed.
A minimum supply is required during
the check.
The minimum amount of recirculated
water should be 10% of the amount
recirculated at the rated load.
The amount of heat consumed should
be reduced as far as possible.
The adjustable high limit ”R” is
bridged. The burner is switched on
until the boiler water temperature
reaches the safety temperature and
the fixed high limit operates.
When the burner is switched off by
the fixed high limit, release the ”TUV”
button, wait until the boiler water
temperature has fallen 15 to 20°C / 27
to 36°F below the selected safety
temperature and then reset the fixed
high limit by pressing the ”E” button.

5351 338 v1.8

86
 Start-up

Steps (continued)

3. Integrate the control unit in the LON BUS system Single-boiler system only

The LON communication module

(accessory) must be inserted
(see page 111).

Set the LON participant number

Set the LON participant number via See page 115 for coding 1.
coding address ”77” in coding 1
(factory setting: ”77: 1”). Please note:
The same number must not be
assigned twice within a LON BUS
system.

Update the LON participant list

This is only possible when all participants are connected and the control unit is
coded as the error manager (coding ”79: 1”).

1. Press w and simultaneously for The participant check is initiated

1234567 approx. 2 seconds. (see also page 88).

2. Press D. The participant list is updated after

approx. 2 minutes.
The participant check is terminated.

Example of single-boiler system with Vitotronic 050 heating circuit controls and Vitocom connected downstream

Vitotronic 100 Vitotronic 050 Vitotronic 050 Vitocom

LON LON LON

Participant No. 1 Participant No. 10 Participant No. 11 Participant No. 100

Coding ”77: 1” Coding ”77: 10” Set coding ”77: 11”
Control unit is error Control unit is not error Control unit is not error Unit is error manager
manager manager manager
Coding ”79: 1” Coding ”79: 0” Coding ”79: 0”
––– Transmit time via LON Time is received via LON Time is received via LON
Set coding ”7b: 1” Set coding ”81: 3”
––– Transmit outdoor Outdoor temperature is –––
temperature via LON received via LON
5351 338 v1.8

Set coding ”97: 2” Set coding ”97: 1”

87
Start-up

Steps (continued)

4. Carry out participant check Single-boiler system only

The participant check is used to verify the communication of the system units
connected to the error manager.
Requirements:
The control unit must be coded as the error manager (coding ”79: 1”)
The LON participant number must be coded in all control units (see page 87)
The participant list must be updated in the error manager (see page 87)

1. Press w and simultaneously for The participant check is initiated.

1234567 approx. 2 seconds. All 7 arrows appear in the display
window.

Participant number
Consecutive list number

2. Select the required participant with

1234567 or .

3. Activate the check with . The arrows in the display will flash
If communication between the two until the check is completed. The
units is verified, the arrows in the display window and all lit buttons of
display window stop flashing. the selected participant flash for
If communication is not verified, the approx. 60 seconds.
display shown on the left appears. Check the LON connection (see page
111).
4. To check further participants, follow
the steps described in points 2 and
3.

5. Press w and simultaneously for The participant check is terminated.

1234567
approx. 1 second.
5351 338 v1.8

88
 Start-up

Steps (continued)

5. Match the control unit to the system type

Set the following coding addresses in See page 117 for coding 2.
coding 2:
”00” System type
”01” Single or multi-boiler system
”02” Burner type
”03” Oil or gas-fired operation
”07” Boiler number
”0C” Return temperature raising
”0d” Therm-Control is effective for ...
”4C” plug sÖ function
”4d” plug sL function
”4E” plug gS function

6. Check outputs (actuators) and sensors

Carry out relay test

Relay test is activated.
1. Press and simultaneously for
approx. 2 seconds.
1234567

2. Select relay outputs with the or

button.
Relay test is terminated.
3. Press .

The following relay outputs can be Display Relay function

selected depending on the system
equipment installed: 11 Burner/stage 1 ON

12 Burner stage 1 and 2

ON/modulation open

13 Burner modulation neutral

14 Burner modulation closed

15 Output 20 ON

16 Output 29 ON

17 Output 52 open

18 Output 52 neutral

19 Output 52 closed

10 DHW pump ON

11 Central fault indicator ON

Check sensors
Scanning of operating status
1. Press . information is activated
5351 338 v1.8

1234567

(see page 97).

2. Scan sensors with or .
Scanning is terminated.
3. Press .

89
Start-up

Steps (continued)

7. Match the coding addresses

Match control unit to modulating burner

Please note:
The burner must be adjusted. In order to achieve a wide modulation range, the
minimum output should be set as low as possible (take chimney/flue system into
account).

1. Start up the burner. The relay test is activated.

2. Press 9 and simultaneously for

approx. 2 seconds.

3. With activate the function

”Modulating burner open” (display:
2) and wait until the actuating drive
of the burner is at maximum output.
Make a note of the value.
4. Establish the maximum burner
output through the fuel Make a note of the value.
consumption.

5. With activate the function

”Modulating burner closed”
(display: 4) and measure the time it
takes for the actuating drive of the
burner to reach the minimum Make a note of the value.
output.

6. Establish the minimum burner output

(basic output) through the fuel
consumption.

7. With activate the function

”Modulating burner open” (display:
2) and, after one-third of the time
measured in point 5, activate the
function ”Modulating burner neutral”
with (display: 3).

Make a note of the value.

8. Establish the partial output through The relay test is terminated.

the fuel consumption.

9. Press .
5351 338 v1.8

90
 Start-up

Steps (continued)

7. Match the coding addresses (continued)

10. Set the established values in coding See page 115 for coding 1.
level 1.

Address Setting of
05 the partial output (see point 8) as a percentage proportion of the
max. output; e.g.
partial output: 170 kW
max. output: 210 kW
170 kW x100 % = 81 %
210 kW
08 units and tens digits of the maximum output established in point
4: e.g. max. output: 210 kW – here set: 10
09 hundreds digit of the maximum output established in point 4: e.g.
max. output: 210 kW – here set: 2
0A the basic output (see point 6) as a percentage proportion of the
max. output; e.g.
basic output: 70 kW
max. output: 210 kW
70 kW x100 % = 33 %
210 kW
15 the operating time in seconds established in point 5

Please note:
You will find details of other possible settings in the sections entitled
”Coding 1” and ”Coding 2” (see page 115 and 117).
5351 338 v1.8

91
Scanning service information

Overview of Service Levels

Function Button combination To exit Page

Temperatures, boiler coding Press 9 and rw simultaneously Press OK 93
cards and scans for approx. 2 seconds
Relay test Press 9 and OK simultaneously for Press OK 89
approx. 2 seconds
Participant check Press w and OK simultaneously for Press w and OK simultaneously for 88
(in conjunction with LON) approx. 2 seconds approx. 1 second
Operating status information Press  Press  97
Service display Press OK 98

5351 338 v1.8

92
 Scanning service information

Temperatures, Boiler Coding Cards and Scans

1. Press and simultaneously for Access diagnosis level.

approx. 2 seconds.

2. Select the required data for scanning

with the or button.

3. Press . Exit diagnosis level.

The following values can be scanned depending on the system equipment

installed:
Display Meaning Notes

08888 Scan 0 Only in conjunction with LON

communication module; see
page 94

18888 Scan 1 Only in conjunction with LON

communication module; see
page 94

28888 Scan 2 Only in conjunction with LON

communication module; see
page 94

3 65 °C Set-point boiler water tempera-

ture (effective set-point value
–––

including boiler protection)

h 70 °C Maximum request temperature –––

48888 Scan 4 See page 95

5 55 °C Set-point domestic hot water

temperature
–––

8230 °C Maximum flue gas

temperature
See coding address ”1F”; can
be reset to the actual value by
pressing D

c1010 Boiler coding card See page 112

b 8d8 Scan b/d See page 95

l8888 Scan L See page 96

o8888 Scan o See page 96

5351 338 v1.8

93
Scanning service information

Temperatures, Boiler Coding Cards and Scans (continued)

Scan 0

0 8 8 8 8
SNVT configuration
0 Auto
1 Tool
0
to Software version
0 0 F Communication coprocessor
to to
9 9 LON participant number

0 Scan 0

Scan 1

1 8 8 8 8
0 0
to to
F F Node address
0
to System number
0 F (only with self-binding)
to
F Subnet address

1 Scan 1

Scan 2

2 8 8 8 8
0 0
to to Software version
5351 338 v1.8

0 0 F F LON communication module

to to
9 9 Number of LON
participants
2 Scan 2

94
 Scanning service information

Temperatures, Boiler Coding Cards and Scans (continued)

Scan 4

4 8 8 8 8
0
to Software version
F Control unit
0
to Software version
1 F Programming unit
or
2 System type

Free

4 Scan 4

Scan b/d

b 8 8 d 8
Isolation valve
0 Closed
1 Preheating
2 Closing
3 Regulating
4 Opening
5 Open
6 Run-on

d Scan d

Burner
0 OFF
1 1st stage/basic load
2 2nd stage/full load
Free
b Scan b
5351 338 v1.8

95
Scanning service information

Temperatures, Boiler Coding Cards and Scans (continued)

Scan L

l 8 8 8 8
0 0 0 Output reduction
or to to (0 to 100 %; 0 = OFF)
1 9 9
Free
L Scan L

Scan o

o 8 8 8 8

Free

Free
0 0
to to
F F Equipment identification code

o Scan o

5351 338 v1.8

96
 Scanning service information

Scanning Service Information

1. Press . Operating status scanning mode is

activated.
2. Select the required operating status
data for scanning with the or
button.

3. Press . Exit the operating status scanning

mode.

The following operating status information can be scanned depending on the

system equipment installed:

Display Meaning Notes

0 01 LON participant number Only displayed if LON

communication module is
connected

3 65 °C Boiler temperature ––

5 50 °C DHW tank temperature

(1st DHW tank temperature
Only displayed if DHW tank
temperature sensor is
sensor) connected

5o 45 °C DHW tank temperature

(2nd DHW tank temperature
Only displayed if DHW tank
temperature sensor is
sensor) connected

6 55 °C Return temperature
17A (1st return temperature
Only displayed if return
temperature sensor is
sensor) connected

8 190 °C Flue gas temperature Only displayed if flue gas

temperature sensor is
connected

9 60 °C Return temperature
17B (2nd return temperature
Only displayed if return
temperature sensor is
sensor) connected
Y Burner hours run The hours run can be reset to
63572 h
1st stage ”0” by pressing D. The hours
run displayed are approximate
values only
YY Burner hours run The hours run can be reset to
09572 h
2nd stage ”0” by pressing D. The hours
run displayed are approximate
values only
YYY Burner starts The number of burner starts
30417 can be reset to ”0” by
pressing D
5351 338 v1.8

97
Scanning service information

Scanning and Resetting the Service Display

Please note:
If a service is carried out before the service display appears, set the coding
address ”24: 1” and then coding address ”24: 0”.

When the limit values selected via

coding addresses ”1F”, ”21” and ”23”
(see page 120) are reached, one of the
following displays flashes on the
programming unit:

Display Meaning

a 245 °C Max. flue gas

temperature reached

35510 h Number of burner hours

run reached

12 u Time interval
(e.g. 12 months)
reached

1. Scan the service messages with the

or button.

2. Press . The service display is turned off.

Please note:
An acknowledged service message
can be displayed again by pressing
(for approx. 3 seconds).

After carrying out maintenance

1. Reset coding ”24: 1” Please note:

(see page 120) to ”24: 0”. If coding address ”24” is not reset,
the service display will re-appear on
Monday morning.

2. If necessary: See ”Temperatures, boiler coding

Press . cards and scans” on page 93.

Reset burner hours run and
number of burner starts with
the button.

Press .

See ”Scanning operating status

3. If necessary: information” on page 97.

Press and
simultaneously for approx.
4 seconds.
5351 338 v1.8

Reset maximum flue gas

temperature (8) to the actual
value by pressing .

Press .

98
 Troubleshooting

Troubleshooting Steps

Page
Diagnosis 1. Establish fault message or ascertain behaviour of system

2. Look for the corresponding cause of the fault in the

diagnosis tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Please note:
Retrieve fault codes from the fault memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

3. Establish the action required in the table

Correction 4. Correct the fault

5351 338 v1.8

99
Troubleshooting

Diagnosis

Faults with fault display on the programming unit

The red fault indicator 2 flashes whenever there is a fault.

1234567

When a fault message is transmitted, The meaning of the fault code is

a fault code flashes in the display 1 explained in the table on page 101
of the programming unit. onwards.

Other fault codes which may be The fault can be acknowledged by

stored can be called up by pressing pressing .The fault message in
the or button. the display 1 is blanked out; the
red fault indicator 2 continues to
Fault symbol flash. The central fault indicator
connected to plug gÖ is switched
Fault code off.

Fault number If an acknowledged fault is not

rectified within 24 hours, the fault
message will re-appear in the
display.

Vitotronic 100 as error manager

A fault on another LON participant is
displayed as shown:

Fault symbol

LON participant number of the unit

with the fault

”EE” = External fault

To retrieve an acknowledged
fault message
Press for approx. 2 seconds; Fault is displayed.
select the acknowledged fault by
pressing the or button.
5351 338 v1.8

100
 Troubleshooting

Diagnosis (continued)

Faults with fault display on the programming unit (continued)

Fault Behaviour of system Cause of fault Action

code in
display

30 Burner is switched on and off by

the adjustable high limit
Short circuit
Boiler temperature sensor
Check boiler temperature sensor (see
page 50)

38 Burner is switched on and off by

the adjustable high limit
Open circuit
Boiler temperature sensor
Check boiler temperature sensor (see
page 50)

50 DHW pump ON:

set-point boiler temperature =
Short circuit
DHW tank temperature sensor 1
Check DHW tank temperature sensor
(see page 51)
set-point DHW tank temperature,
priority controls are cancelled
or
In conjunction with DHW heating:
Tank heating is switched on and off
by Tank temperature sensor 2

51 In conjunction with DHW heating:

Tank heating is switched on and off
Short circuit
DHW tank temperature sensor 2
Check DHW tank temperature sensor
(see page 51)
by Tank temperature sensor 1

58 DHW pump ON:

set-point boiler temperature =
Open circuit
DHW tank temperature sensor 1
Check DHW tank temperature sensor
(see page 51)
set-point DHW tank temperature,
priority controls are cancelled
or
In conjunction with DHW heating:
Tank heating is switched on and off
by Tank temperature sensor 2

59 In conjunction with DHW heating:

Tank heating is switched on and off
Open circuit
DHW tank temperature sensor 2
Check DHW tank temperature sensor
(see page 51)
by DHW tank temperature sensor 1

60
No output reduction

Return control open
Short circuit
Temperature sensor aJA
Check temperature sensor
(see page 52)

Boiler with maximum temperature

68
No output reduction

Return control open
Open circuit
Temperature sensor aJA
Check temperature sensor
(see page 52)

Boiler with maximum temperature

70 Shunt pump ON continuously Short circuit

Temperature sensor aJB
Check temperature sensor
(see page 52)
In conjunction with DHW heating:
Mixing valve of primary circuit
closed, no domestic hot water
heating

78 Shunt pump ON continuously Open circuit

Temperature sensor aJB
Check temperature sensor
(see page 52)
In conjunction with DHW heating:
Mixing valve of primary circuit
closed, no domestic hot water
heating
5351 338 v1.8

101
Troubleshooting

Diagnosis (continued)

Faults with fault display on the programming unit (continued)

Fault Behaviour of system Cause of fault Action

code in
display
Insert plug aJA
aa Controlled operation Therm-Control configuration
error: On Vitocrossal:
plug aJA of Check that coding ”0d: 0” is set.
Therm-Control temperature
sensor not inserted
Insert plug aJB and check coding
ab Controlled operation, DHW tank
may be cold
DHW heating
configuration error:
Coding ”55: 3” is set, but
plug aJB is not inserted
and/or
coding ”4C: 1” and ”4E: 1”
not set
Insert plug aJA and check coding
aCc Controlled operation Return temperature sensor
configuration error:
Coding ”0C: 1” is set, but
plug aJA is not inserted
and/or
coding ”4E: 0” is not set

aCd Controlled operation Butterfly valve

configuration error:
If butterfly valve is installed:
Set coding ”4E: 0”
Coding ”0C: 2”, ”0C: 3” or If no butterfly valve is installed:
”0C: 4” is set, Set coding ”0C: 0” or ”0C: 1”
and
coding ”4E: 1” is set

b0 Controlled operation Short circuit

Flue gas temperature sensor
Check flue gas temperature sensor
(see page 53)

b1 Controlled operation Communication error

Programming unit
Check connections, if necessary
replace programming unit

b4 Emissions test mode Internal fault Check electronics board

b5 Controlled operation Internal fault Check electronics board

b6 Operation at constant temperature Invalid hardware code Check the control software circuit
board and confirm the coding address:
- Enter coding 2 (see page 117
for instructions).
- Change code 8A to 176.
- Confirm coding 92:160

b7 Boiler controlled on basis of

adjustable high limit
Internal fault
Boiler coding card
Insert boiler coding card or replace
if defective (see page 42)

b8 Controlled operation Open circuit

Flue gas temperature sensor
Check flue gas temperature sensor
(see page 53)

bf Controlled operation Incorrect LON communication

module
Replace LON communication
module
5351 338 v1.8

c1 Boiler cools down External safety equipment
Check connection of plug

aBÖ

Check external safety
equipment

102
 Troubleshooting

Diagnosis (continued)

Faults with fault display on the programming unit (continued)

Fault Behaviour of system Cause of fault Action

code in
display

c4 Control mode Faulty communication with Input

Module
Check connections and
cables/leads; replace Input
0 to 10 V Module, if required
(see page 126)
Without Input Module:
Set coding 9d: 0

c8 Boiler cools down Error

Low water indicator
Check water level of system,
reset low water indicator

c9 Boiler cools down Error

Maximum pressure limiter
Check system pressure, reset
maximum pressure limiter

ca Boiler cools down Error

Minimum pressure limiter or
Check system pressure, reset
minimum or maximum pressure
maximum pressure limiter 2 limiter

cb Boiler cools down Error

Additional fixed high limit or limit
Check system pressure, reset
fixed high limit or flue gas
thermostat or flue gas damper damper

cd Controlled operation Communication error

Vitocom
Check connections and
Vitocom

cEe Controlled operation Communication error

Plug-in adaptor for external
safety equipment

cf Controlled operation Error

LON communication module
Replace communication
module

d1 Boiler cools down Burner fault Check burner

d4 Boiler cools down Fixed high limit has operated Check fixed high limit reset to
25° C (+/- 5.0° C)
Cooler than the high limit set
Check connection at inputs
d6 Controlled operation Fault at ”DE1” in the plug-in
adaptor for external safety ”DE1” to ”DE3”
equipment

d7 Controlled operation Fault at ”DE2” in the plug-in

adaptor for external safety
equipment

d8 Controlled operation Fault at ”DE3” in the plug-in

adaptor for external safety
equipment

e0 Controlled operation Open circuit

LON communication module
Check connection
5351 338 v1.8

103
Troubleshooting

Diagnosis (continued)

Retrieving fault codes from the fault memory (error history)

All faults which have occurred are stored and can be retrieved by scanning.
The scanning sequence starts with the most recently stored fault code.

1. Press and simultaneously Scanning of error history is

1234567

for approx. 2 seconds. activated.

2. Access the individual fault codes All stored fault codes can be
by pressing the or button. deleted by pressing .

Sequence of Fault code

stored fault
codes

1 Last (most recent)

fault code
.. ..
. .

10 Last fault code

3. Press . Scanning of error history is

terminated.

5351 338 v1.8

104
 Functional description

Boiler Temperature Control

Brief description

The boiler water temperature is In conjunction with Therm-Control: Coding addresses which influence
controlled by switching the burner on The set-point boiler water temperature the boiler temperature control
and off. is increased when the temperature falls 02 to 06, 08 to 0b, 13 to 1C.
The set-point boiler water temperature below the set-point value on the sensor
value is determined by the set-point of the Therm-Control.
supply temperature values of the boiler
circuit (A1), the heating circuits with
mixing valve (from Vitotronic 050) and
the set-point supply temperature value
preset via coding address ”9b” as well
as the set-point domestic hot water
temperature, and is dependent on the
boiler and the heating and control
facilities installed.

Functions

The boiler water temperature is Upper limits of control range Lower limit of control range
measured via a multiple sensor well by
Fixed high limit FHL
The control unit regulates the boiler
three sensors separately: 110°C / 230°F, can be adjusted to water temperature in normal

Fixed high limit FHL 100°C / 212 or 230°F operation and in the frost protection
(liquid expansion)
Adjustable high limit AHL mode according to the boiler

Adjustable high limit AHL 95°C/ 203°F, can be adjusted to concerned (boiler coding card).
(liquid expansion) 100°C / 212°F

Boiler temperature sensor BTS
Electronic maximum limit
(change in resistance PT 500) Setting range: 20 to 127°C /
68 to 261°F
The maximum limit for the boiler
water temperature is defined in
coding address ”06”.

Control sequence

Boiler temperature falls Boiler temperature rises

The burner override signal is set for a The switch-off point of the burner is
boiler water temperature setpoint value defined by the switch-off differential
of –2°C / -4°F, and the burner starts (coding address ”13”).
its own monitoring program. Depending
on the range of additional control
facilities and the method of firing,
burner override can be delayed by a
few minutes.
5351 338 v1.8

105
Functional description

Heating Circuit Control

Brief description

The supply temperature of the boiler Coding addresses which influence the
circuit (A1) corresponds to the boiler heating circuit control
water temperature. 55, 56, 58, 5A to 63, 6A, 6b.

Functions

The boiler circuit (A1) is dependent on Upper limit of control range Domestic hot water temperature
the boiler water temperature and its Electronic maximum limit
With priority control:
control range limits. Setting range: 1 to 127°C / While the DHW tank is being
34 to 261°F. heated, the set-point supply
Change via coding address ”C6”. temperature value is set to
0°C / 32°F.
Lower limit of control range
Without priority control:
Electronic minimum limit The heating circuit control
Setting range: 1 to 127°C / continues to operate as normal
34 to 261°F. with the setpoint value unchanged.
Change via coding address ”C5”.

DHW Tank Temperature Control

Brief description

The DHW tank temperature control is a The switching differential is ±2.5°C / coding address ”60”) and space
constant value control. It operates on 4.5°F. heating is switched off (DHW tank
the basis of switching the DHW pump During DHW tank heating, a constant priority control optional).
on and off. maximum boiler water temperature is
set (20°C / 36°F above the set-point
DHW tank temperature, variable via

Functions

Frost protection function Heating with the additional function Additional control facilities
If the domestic hot water temperature takes place daily at the time of the The domestic hot water supply
falls below 10°C / 50°F, the domestic 1st domestic hot water heating can be blocked and released via
hot water DHW tank is heated to period. change-over of the heating program.
20°C / 68°F.
Set-point domestic hot water System with DHW heating
Additional function for domestic hot temperature The functions described above also
water heating The set-point domestic hot water apply in conjunction with DHW
For temporarily increasing the DHW temperature can be set in the range of heatings.
tank temperature at selectable intervals 10 to 60°C / 50 to 140°F. The
→ this provides additional assurance setpoint range can be extended to Set the following codings:
that bacteria are eliminated. 95°C / 203°F via coding address ”4C: 1”, ”4E: 1”, ”55: 3”.
This function is activated when a ”56”.
5351 338 v1.8

second DHW setpoint value is selected

via coding address ”58” and a time is
selected via coding address ”63”.

106
 Functional description

DHW Tank Temperature Control (continued)

Control sequence

DHW tank temperature falls DHW tank temperature rises

(Set-point value –2.5°C / - 4.5°F, (Set-point value +2.5°C / 4.5°F)

selectable via coding address ”59”) The boiler water temperature set-point
The set-point boiler water temperature value is reset to the value
is set 20°C / 36°F higher than the determined by the set-point supply
DHW temperature set-point value temperature of the boiler circuit.
(selectable via coding address ”60”).

The DHW pump is switched on
When the DHW tank has been
immediately (Coding ”61: 1”). heated up, the DHW pump continues
to run (coding ”62: 10”) until
Boiler temperature-dependent switching - the temperature difference
of the DHW pump between the boiler water and
(Coding ”61: 0”): domestic hot water is less than
The circulation pump is switched on 7°C / 13°F or
when the boiler water temperature is - the set-point boiler water
7°C / 13°F higher than the domestic temperature selected through the
hot water temperature. set-point supply temperature of the
boiler circuit is reached
or
- the set-point domestic hot water
temperature is exceeded by
5°C / 9°F.
The max. run-on time is 15 minutes
(selectable via coding address ”62”).

DHW pump without run-on time

(Coding ”62: 00”):
The circulation pump is switched off
immediately.

With adaptive DHW tank heating

(Coding ”55: 1”):
Adaptive DHW tank heating takes
into account the rate at which the
temperature increases during
domestic hot water heating.
It also takes into account whether
the boiler must supply heat for space
heating purposes after heating up the
DHW tank or whether the residual
heat of the boiler should be
transferred to the DHW tank.
The control unit determines the
switch-off time of the burner and the
circulation pump accordingly so that
the set-point domestic hot water
temperature is not substantially
exceeded after DHW tank heating is
completed.
5351 338 v1.8

107
Additional information

Overview

Page

Technical Data 105

System Components
Line voltage motherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Low-voltage motherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Power supply unit board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Electronics board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Optolink/override switch board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Programming unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Fuse box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
LON communication module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Boiler coding card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
TUV button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Fixed high limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Adjustable high limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Input module 0 to 10V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Resetting codings to the factory setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Coding 1
Call up coding level 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Codings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Coding 2
Call up coding level 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Reset codings to factory settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Overview of all codings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Wiring Diagrams
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Low-voltage motherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Line voltage motherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Parts List
GCI Series 126
5351 338 v1.8

108
 Additional information

Technical Data

Rated voltage: 120 V~ Ambient Relay outputs at 120 V~ for

Rated frequency: 60 Hz temperature
control
Rated actual: 2 x 6 A~
during output sÖ: 2 FLA, 120 VAC*1
Power operation: 0 to 40°C /
circulation pump
consumption: 10 W 32 to 104°F for heating the
Protection For use in boiler DHW tank sA: 2 FLA, 120 VAC*1
class: I rooms (normal
shunt pump or
Degree of ambient conditions) boiler circuit
protection: IP 20 D to EN
during pump sL: 2 FLA, 120 VAC*1
60 529, to be storage and
central fault
guaranteed by transport: –20 to 65°C / indicator gÖ: 2 FLA, 120 VAC*1
mounting/integration -4 to 149°F
boiler isolation
valve gS: 0.1 FLA, 120 VAC*1
or
return valve 0.15 FLA, 24 VAC

burner
connection fA: 4 FLA 120 VAC
connection lÖ:
– 2-stage: 0.5 FLA, 120 VAC
– modulating: 0.1 FLA, 120 VAC

*1 Total max. 6 A 120 VAC

System Components

Line voltage motherboard, Part No. 7165 792

The motherboard contains:

relays and outputs for activating
the pumps, the control elements
and the burner

plug-in location for power supply
unit board and boiler control section.

Low-voltage motherboard, Part No. 7820 290

The motherboard contains:

plugs for sensors, communication
connections and external equipment

plug-in locations for electronics
board, LON communication module,
Viessmann 2-wire BUS
communication module,
programming unit, boiler coding
card and Optolink board.
5351 338 v1.8

109
Additional information

System Components (continued)

Power supply unit board, 120 VAC Part No. 7823 991

The power supply unit board contains

the low-voltage supply for the entire
electronics.

Electronics board, Part No. 7828 193

The board contains the microprocessor

with the software.

When replacing the board:

1. Make a note of codings and settings
on the control unit.
2. Replace the board.
3. Set coding ”8A:176” and set
cod-ing address ”92” (not listed in
the overview) to ”92:160”.

Optolink/override switch board, Part No. 7820 165

The circuit board contains: Override switch for flue gas

Operating status indicator measurements with the boiler operated

Fault indicator with constant boiler water temperature

Optolink laptop interface for a short time.

Override switch
The following functions are triggered in
the ”h” setting:

The burner is switched on
(this can be delayed if the system
incorporates a fuel preheater or flue
gas damper)

All pumps are switched on

The boiler water temperature is
controlled by the adjustable high limit
”R”.
5351 338 v1.8

110
 Additional information

System Components (continued)

Programming unit, Part No. 7823 990

The programming unit is inserted in the

control unit.

For setting:

heating program

set-point values

For displaying:

temperatures

operating status information

faults

Fuse box, Part No. 7820 175

The fuse box contains:

fixed high limit

adjustable high limit

fuses

heating system switch

TUV button

LON communication module, Part No. 7172 173 Accessory

The communication module is inserted

A A A
in the control unit.
Interruption of communication is
LON

LON

D
LON

LON
LON

LON

indicated.
D
1 terminal resistor is inserted on each
of the first and last control unit.

C B B C A Control unit or Vitocom

B Connecting cable for data transfer
between the control units (part of
standard delivery or accessory)
C Terminal resistor,
(Part No. 7143 497, see Vitotronic
5351 338 v1.8

050 or Vitotronic 333)

D Plug-in locations for B and C

111
Additional information

System Components (continued)

Boiler coding card

Vitotronic 200 Boiler coding Part No.

in conjunction with card
Vitocrossal 300, Type CT3 1040 7820 144
Vitorond 200, Type VD2/VD2A 1020 7820 142
Vitocrossal 200, Type CM2 1041 7820 145

Fuses

F1: 6.3 A, 250 V for protecting

the control elements, pumps and
electronics.
Mounting location: see drawing.

F2: T6.3 A, 250 V for protecting

the burner.
Mounting location: see drawing.

F1

F2

5351 338 v1.8

112
 Additional information

System Components (continued)

TUV button, Part No. 7819 314

For checking the fixed high limit.

See description on page 86.

Fixed high limit, Part No. 7820 036

Type STW 56.10525.570, make: EGO, DIN STB (STW) 106095

or
EM-80-V-TK/b7-1 60002843, make: Juchheim, DIN STB 82699

The fixed high limit has a factory setting of 120°C / 248°F.

Electromechanical temperature switch based on the liquid expansion principle
with interlock

Intrinsically safe; interlocking also takes place if the capillary tube is leaking or
if ambient temperatures are below –10°C / 14°F

Limits the boiler water temperature to the maximum permissible value by
cutting out and interlocking

Can be adjusted with the slotted screw A at the rear of the unit to 110 and
99 °C / 230 and 210 °F (cannot be reset to 120°C / 248 °F once adjusted)

Reset unit by pressing the reset button ”E” on the front of the programming
unit if the temperature has fallen approx. 15 K below the shut down temperature

Central fastening M 10, capillary 3600 mm long

Tests:
Electrical to VDE 0701 standard
Functional check via TEST button

Adjustable high limit, Part No. 7817 531

Type TR 55.18029.020, make: EGO, DIN TR 110397

or
EM-1-V-TK/b1 60002846, make: Juchheim, DIN TR 77798

The adjustable high limit has a factory setting of 95°C / 203°F

Electromechanical temperature switch based on the liquid expansion principle

Controls the maximum boiler water temperature (e.g. in emissions test mode)

Can be adjusted to 100 and 110°C / 212 and 230°F by altering the setting
of the stop dial or by removing the cams

IMPORTANT
Set the lower limit at least 20°C / 36°F higher than the domestic hot water
temperature, the upper limit at least 15°C / 27°F lower than the fixed high limit.

Adjusting shaft 6 mm / 0.27 inches, flat topped
Adjusting knob pushed onto shaft from front

Capillary 3600 mm / 141.7 inches long
Sensor 3 mm / 0.1inches thick, 180 mm / 7.1inches long

Tests:
Electrical to VDE 0701 standard
5351 338 v1.8

Functional check via emissions test mode

113
Additional information

System Components (continued)

Input Module 0 to 10 V, Part No. 7134 561

From software version 7 of Vitocontrol-S, VD2/CT3, the Input Module can be connected (software version via scan 2:
1st digit, display ≥7).

For external control of the boiler/supply temperature via a 0 to 10VDC signal

10 to 100˚C or 30 to 120˚F
50 to 212˚C or 86 to 248˚F
or
to signal reduced mode and regulate a heating circuit pump to a lower speed.
24V
5V

Electronics

B
F1 ON
50mA
(slow)
OFF 1 2 3 4
L1 N S Ö P 1 2 3 1 2 3
40
120 VAC _ +

A
157 144 145

fÖ Power connection A Power supply

aVF 0 to 10VDC input (provide disconnect if required by
aVG KM BUS to control unit code)
aBJ Potential free output contact B DIP switch (see table)

DIP switch Function

1 to 3: OFF Switch for pre-set value
1: ON Reduced mode – system circuit A1
2: ON Reduced mode – mixing valve circuit M2
3: ON Reduced mode – mixing valve circuit M3
4: ON Pre-set value default 10 to 100˚C / 50 to 212˚F
4: OFF Pre-set value default 30 to 120˚C / 86 to 248˚F

Please note:
Amongst switches 1 to 3, only one switch may be set to ON.

Resetting codings to the factory setting

1234567 1. Press w and rw simultaneously

for approx. two seconds, until the
first two arrows appear in the
5351 338 v1.8

display.

2. Press D.

114
 Additional information

Coding 1

Call up coding level 1

1. Press and simultaneously for Access coding level 1.

approx. 2 seconds. The first arrow appears in the
display.

2. Call up the required coding address Address flashes.

with the or button;
press to confirm. Value flashes.

3. Change the value with the or The value is stored and stops flashing
button; press to confirm. for approx. 2 seconds. Then the
address flashes and further addresses
can now be selected with the or
button.

4. Press and simultaneously for Exit coding level 1.

approx. 1 second.

Codings

Coding as per Function New coding Possible change

factory setting
Address: Value Address:Value
00: 1 System System circuit A1 00: 2 System circuit A1
type without domestic hot water with domestic hot water heating
heating
01: 1 System Single-boiler system 01: 2 Multi-boiler system with cascade control
type via LON BUS (e.g. Vitotronic 333, Type
MW1)
01: 3 Multi-boiler system with cascade control
via switch contacts (input aVD and aVH)
or 0-10V input module
02: 1 Boiler/ Operation with two-stage 02: 0 Operation with single-stage burner
burner burner 02: 2 Operation with modulating burner
03: 0 Boiler/ Gas-fired operation 03: 1 Oil-fired operation
burner (coding cannot be reset)
05: 70 Burner Burner curve 05: 0 Burner curve linear
(mod.) 05: 1 Burner curve not linear:
to
05: 99 Partial output in kW (at g of the
Operating
time of the actuating drive)
x100%
Max. output in kW
5351 338 v1.8

= Partial output in %
06: 87 Boiler/ Max. limit of boiler water 06: 20 Maximum boiler water temperature limit
burner temperature set to to variable between
87°C / 189°F 06:127 20 and 127°C / 68°F and 261°F

115
Additional information

Coding 1 (continued)

Codings (continued)

Coding as per Function New coding Possible change

factory setting
Address: Value Address:Value
07: 1 Boiler Boiler sequence number in multi- 07: 2 Boiler sequence number in multi-boiler
boiler system (in conjunction with to system (in conjunction with coding
coding address ”01”) 07: 4 address ”01”)
08:*1 Burner Max. output of burner in kW 08: 0 Maximum output variable from
(mod.) to 0 to 99 kW;
08: 99 1 increment = 1 kW
09:*1 Burner Max. output of burner in kW 09: 0 Maximum output variable from
(mod.) bis 0 to 19900 kW:
09:199 1 increment = 100 kW
0A:*1 Burner Basic output of burner in % 0A: 0 Basic output in kW
x100% =
(mod.) to Max. output in kW
0A:100 Basic output in %
15: 10*2 Burner Operating time of actuating drive 15: 5 Operating time variable
(mod.) to from 5 to 199 seconds
15:199
40:125 General Operating time of actuating drive, 40: 5 Operating time adjustable
boiler isolation valve, 3-port mixing to from 5 to 199
valve or mixing valve motor in 40:199
conjunction with return
temperature control 125 minutes
77: 1 General LON participant number 77: 2 LON participant number
to selectable from 1 to 99
77: 99 Please note:
Each number may be assigned once only.
*1 The factory setting is determined by the boiler coding card.
*2 This setting is matched to the Vitocrossal.

5351 338 v1.8

116
 Additional information

Coding 2

Call up coding level 2

The overview lists all possible coding addresses.

However, only those coding addresses are displayed which correspond to the
system type and equipment concerned and can be changed accordingly.

1. Press and simultaneously Access coding level 2.

1234567 for approx. 2 seconds; The first two arrows appear in
press to confirm. the display.

2. Select the required coding address Coding address flashes.

1234567 with the or button;
press to confirm.

3. Change the value with the or The value is stored and stops
button; flashing for approx. 2 seconds.
press to confirm. Then the address flashes and
further addresses can now be
selected with the or
button.

4. Press and simultaneously Exit coding level 2.

for approx. 1 second.

Reset codings to factory settings

1. Press and simultaneously Access coding level 2.

1234567 for approx. 2 seconds.

2. Press . The codings are reset to their

factory settings. The display
changes and shows the boiler
water temperature.

Overview of all codings

Coding as per Function New coding Possible change

factory setting
Address: Value Address: Value
00: 1 System System circuit A1 without 00: 2 System circuit A1
type domestic hot water heating with domestic hot water heating
01: 1 System Single-boiler system 01: Multi-boiler system with cascade
type control via LON BUS (e.g.
Vitotcontrol-S, VD2/CT3, Model MW1)
01: 3 Multi-boiler system with cascade
control via switch contacts
5351 338 v1.8

02: 1 Boiler/ Operation with two-stage 02: 0 Operation with single-stage burner
burner burner 02: 2 Operation with modulating burner

117
Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address: Value
Address: Value
03: 0 Boiler/ Gas-fired operation 03: 1 Oil-fired operation
burner (coding cannot be reset)
04:*1 Boiler/ Switching differential 04: 0 Switching differential 4°C / 7°F
burner

Burner
ON

OFF Time

Set-
point

Low Medium High

heat demand heat demand heat demand

Switching differential heat demand-

controlled

ERB50 function
04: 1 Values from 6 to 12°C / 11 to 22°F are
set, depending on the heat demand.
Burner

ON

OFF Time

Set-
point

Low Medium High

heat demand heat demand heat demand

ERB80 function
Values from 6 to 20°C / 11 to 36°F are
04: 2 set, depending on the heat demand.
Burner

ON

OFF
Time

Set-
point

Low Medium High

heat demand heat demand heat demand
The heat demand-controlled switching
differential takes into account the boiler
load. The switching differential, i.e. the
burner operating time, is varied in
relation to the actual heat demand.
05: 70 Burner Burner curve 05: 0 Burner curve linear
(mod.) 05: 1 Burner curve not linear
to
05: 99 Partial output in kW (at g of the
Operating
time of the actuating drive)
x100 %
Max. output in kW
5351 338 v1.8

= Partial output in %
*1 The factory setting is determined by the boiler coding card.

118
 Additional information

Coding 2 ((continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
06: 87 Boiler/ Max. limit of boiler water 06: 20 Maximum boiler water temperature limit
burner temperature set to to variable between 20 and 127
87°C / 189°F 06:127
07: 1 Boiler Boiler sequence number in multi- 07: 2 Boiler sequence number in multi-boiler
boiler system (in conjunction with to system
coding address ”01”) 07: 4 (in conjunction with coding address ”01”)
08:*1 Burner Max. output of burner in kW 08: 0 Maximum output variable from
(mod.) to 0 to 99 kW;
08: 99 1 increment = 1 kW
09:*1 Burner Max. output of burner in kW 09: 0 Maximum output variable from
(mod.) to 0 to 19 900 kW;
09:199 1 increment = 100 kW
0A:*1 Burner Basic output of burner in % 0A: 0 Basic output in kW
x100% =
(mod.) to Max. output in kW
0A:100 Basic output in %
0C: 5 Boiler Boiler isolation valve controlled on 0C: 0 Without function
a modulating basis independently 0C: 1 Continuous return temperature control
of the set-point boiler water
temperature 0C: 2 Boiler isolation valve time-controlled
0C: 3 Boiler isolation valve temperature-controlled
0C: 4 Boiler isolation valve controlled on a
modulating basis as a function of the set
point boiler water temperature
0d: 2 Boiler With Therm-Control, effective for 0d: 0 Without Therm-Control
boiler isolation valve (function not 0d: 1 With Therm-Control, effective for mixing
active if ”0C: 1” is coded) valve of heating circuits connected
downstream
13:*1 Boiler/ Switch-off differential in °C / °F 13: 0 Without switch-off differential
burner The burner is switched off when 13: 2 Switch-off differential variable from
the boiler water temperature rises to 2 to 20°C / 4 to 36°F
above the set-point value 13: 20
14:*1 Burner Minimum operating time in 14: 0 Minimum operating time variable
minutes to from 0 to 15 minutes
14: 15
15: 10*2 Boiler/ Operating time of actuating drive 15: 5 Operating time variable
burner 10 seconds to from 5 to 199 seconds
(mod.) 15:199
16:*1 Burner Mod. burner offset in °C / °F 16: 0 Offset during optimized start-up
(mod.) Temporary reduction of the boiler to adjustable from 0 to 15°C / 0 to 27°F
set-point value after burner start 16: 15
1A:*1 Burner Optimized start-up in minutes 1A: 0 Duration of optimized start-up
5351 338 v1.8

(mod.) to adjustable from 0 to 60 minutes

1A: 60
*1 The factory setting is determined by the boiler coding card.
*2 These settings are matched to the Vitocrossal.

119
Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
1b: 60 Burner Time from ignition of burner to 1b: 0 Control delay adjustable
start of control 60 seconds to from 0 to 199 seconds
1b:199
1C:120 Burner Start delay 120 seconds (only 1C: 1 Start delay adjustable
selectable if no operating signal to from 1 to 199 seconds
”B4” is available at plug fA of 1C:199
the burner)
1F: 0 Boiler No monitoring of flue gas With flue gas temperature sensor
temperature 1F: 1 connected: When the flue gas
to temperature exceeds the
1F: 50 preselected limit value (selectable
in the range from 10 to 500°C /
50 to 932°F), the service display
appears;
1 increment = 10°C / 50°F
21: 0 Boiler/ No service display for burner 21: 1 The number of burner hours run
burner to before the service display appears
21:100 can be set between 100 and
10000 hours; 1 increment = 100
hours
23: 0 Boiler/ No time interval for burner 23: 1 Time interval variable between
burner maintenance to 1 and 24 months
23: 24
24: 0 Boiler/ No service display 24: 1 The service display appears
burner (address is set automatically and
must be reset manually after
maintenance has been carried out)
26: 0 Boiler/ Fuel consumption of burner 26 : 1 Input from 0.1 to 9.9;
burner (1st stage); not metered if to 1 increment = 10 litres or gallons/hour
(2-stage) ”26: 0” and ”27: 0” are coded 26 : 99
27: 0 Boiler/ Fuel consumption of burner 27: 1 Input from 10 to 1990;
burner (1st stage); not metered if to 1 increment = 10 litres or gallons/hour
(2-stage) ”26: 0” and ”27: 0” are coded 27:199
28: 0 Boiler/ No intermittent ignition of burner 28: 1 The burner is automatically
burner switched on for 30 seconds
after 5 hours
29: 0 Boiler/ Fuel consumption of burner 29: 1 Input from 0.1 to 9.9;
burner (2nd stage); not metered if ”29: 0” to 1 increment = 0.1 litre or gallon/hour
(2-stage) and ”2A: 0” are coded 29: 99
2A: 0 Boiler/ Fuel consumption of burner 2A: 1 Input from 10 to 1990;
burner (2nd stage); not metered if to 1 increment = 10 litres or gallons/hour
(2-stage) ”29: 0” and ”2A: 0” are coded 2A:199
5351 338 v1.8

2b: 5 General Maximum preheating time of 2b: 0 No preheating time

boiler isolation valve 5 minutes 2b: 1 Preheating time selectable from
to 1 to 60 minutes
2b: 60

120
 Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
2C: 5 General Maximum run-on time of boiler isolation 2C: 0 No run-on time
valve 5 minutes 2C: 1 Run-on time adjustable
to from 1 to 60 minutes
2C: 60
2d: 0 Boiler Shunt pump ON only when requested 2d: 1 Shunt pump ON continuously
40:125 General Operating time of actuating drive, boiler 40: 5 Operating time adjustable
isolation valve, 3-port mixing valve or to from 5 to 199 seconds
mixing valve motor in conjunction with 40:199
return temperature raising facility
125 seconds
4A: 0 General Plug aJA not installed 4A: 1 Plug aJA installed
(e.g. temperature sensor of
Therm-Control);
automatically recognized
4b: 0 General Plug aJB not installed 4b: 1 Plug aJB installed
(e.g. temperature sensor T2);
automatically recognized
4C: 2 General Connections at plug sÖ A1: 4C: 1 Primary pump of DHW heating
Therm-Control switch contact 4C: 3 Circulation pump of flue gas/water
heat exchanger
4d: 1 General Connections at plug sL: 4d: 2 Boiler circuit pump
Shunt pump 4d: 3 Boiler circuit pump with boiler
isolation valve function
4E: 0 General Connections at plug gS:
Boiler isolation valve or 3-port mixing 4E: 1 3-port valve of DHW heating
valve for return temperature raising facility
4F: 5 General Shunt pump, boiler circuit pump or 4F: 0 No pump run-on
distributor pump with 5 minutes run-on 4F: 1 Run-on time adjustable
time to from 1 to 60 minutes
4F: 60
54: 0 General Without solar control unit 54: 1 With Vitosolic 100;
will be recognised automatically
54: 2 With Vitosolic 200;
will be recognised automatically
5351 338 v1.8

121
Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
55: 0 DHW Tank heating, 55: 1 Adaptive tank heating active
differential +/- 2.5°C / 4.5°F (takes into account the rate at
which the tank temperature
increases during domestic hot
water heating)
55: 2 Tank temperature control with 2
tank temperature sensors
55: 3 DHW heating circuit temperature
control (sensor 17B if used in
conjunction with mixing valve and
a plate heat exchanger)
56: 0 DHW Setting range of domestic hot water tem- 56: 1 Setting range of domestic hot
perature 10 to 60°C / 50 to 140°F water temperature 10 to 95°C /
50 to 203°F
IMPORTANT

Observe max. DHW temperature

Adjust adjustable high limit ”R”
58: 0 DHW Without additional function for domestic 58: 1 Input of a 2nd set-point DHW
hot water heating to temperature value; variable between
58: 95 1 and 95°C / 34 and 203°F (note
coding address ”56”).
¨ CAUTION

Set the adjustable high limit ”R”
to a value which is at least 10°C/
18°F higher than the maximum
domestic hot water temperature
( the temperature which is reached
by activating the additional function)

The temperature set on the
adjustable high limit ”R” must not
exceed the maximum permissible
tank temperature
See installation
instructions for the DHW
tank concerned

59: 0 DHW Tank heating: 59: 1 Switch-on point variable between 1

Switch-on point – 2.5°C / 4.5°F to and 10°C / 18°F below set point
Switch-off point + 2.5°C / 4.5°F 59: 10 value
5A: 0 DHW Without function 5A: 1 Supply temperature request of DHW tank
is the maximum value of the system
60: 20 DHW When domestic hot water is being 60: 10 Differential between boiler water
heated, the boiler water temperature is a to temperature and set-point DHW
maximum of 20°C / 36°F higher than the 60: 50 temperature adjustable between 10
5351 338 v1.8

set-point domestic hot water temperature and 50°C / 18 and 90°F

61: 1 DHW Circulation pump switches on 61: 0 The circulation pump is switched
immediately on as a function of the boiler
temperature

122
 Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
62: 10 DHW Circulation pump with run-on time of 62: 0 Circulation pump without run-on
10 minutes time
62: 1 Run-on time variable from 1 to 15
to minutes
62: 15
67: 40 DHW With Vitosolic: 67: 0 Without 3rd DHW set-point
3rd DHW set-point 40˚C/ 104˚F
Reloading suppression will be active 67: 1 Input of a 3rd set DHW set-point
above set temperature. DHW tank is to temperature; adjustable
heated only by solar heating system. 67: 95 from 1 to 95˚C / 34 to 203˚F

63: 0 DHW Without additional function for 63: 15 Twice per day
domestic hot water heating
63: 0 DHW Without additional function for 63: 1 Additional function: Once per day
domestic hot water heating 63: 2 Every 2 days
to to
63: 14 Every 14 days
68: 8 DHW In conjunction with 2 tank 68: 2 Factor adjustable from 0.2 to 1
temperature sensors with the DHW to per 1 increment = 0.1
heating: 68: 10
Switch-off point of tank heating at
setpoint value x 0.8
69: 7 DHW In conjunction with 2 tank 69: 1 Factor adjustable from 0.1 to 0.9
temperature sensors with the DHW to per 1 increment = 0.1
heating: 69: 9
Switch-on point of tank heating at
setpoint value x 0.7
76: 0 General Without LON communication module 76: 1 With LON communication module;
recognized immediately
76: 2 With Viessmann 2-wire BUS
communication module; recognized
immediately

77: 1 General LON participant number 77: 2 LON participant number selectable
to from 1 to 99
77: 99 Please note:
Each number may be assigned
once only.
78: 1 General LON communication released 78: 0 LON communication blocked
79: 0 General Control unit is not error manager 79: 1 Control unit is error manager
80: 1 General With 5 seconds time delay for fault 80: 0 Without time delay
message 80: 2 Time delay adjustable between
5351 338 v1.8

to 10 and 995 seconds;

80:199 1 increment = 5 seconds

123
Additional information

Coding 2 (continued)

Overview of all codings (continued)

Coding as per Function New coding Possible change

factory setting Address:
Address: Value Value
88: 0 General Temperatures displayed in Celsius 88: 1 Temperatures displayed in
Fahrenheit
8A:175 General Display of codings which can be set 8A:176 All codings displayed regardless of
for the system type concerned system type and equipment
installed
92:165 General Do not Adjust! Is only displayed if
8A:176 is coded
93: 0 General Central fault indication in emissions 93: 1 Central fault indication in
test mode/service display not emissions test mode/service
effective for central fault display effective for central fault
94: 0 General Without plug-in adaptor for external 94: 2 With plug-in adaptor for external
safety equipment safety equipment; recognized
automatically
98: 1 General Viessmann system number 98: 2 System number
(in conjunction with monitoring of to selectable from 1 to 5
several systems within one LON BUS 98: 5
system)
9b: 0 General Input aVH released 9b: 1 Set-point supply temperature
to selectable via plug aVH from 1 to
9b:127 127°C / 261°F with external
request
9C: 20 General Monitoring of LON participants:
If a participant does not answer 9C: 0 No monitoring
back, default values set within the
control unit are used for the first 20 9C: 1 Time selectable
minutes. Then an error message is to from 1 to 60 minutes
transmitted. 9C: 60

9d: 0 General Without Input Module 9d: 1 With Input Module 0 - 10V;
0 to 10V will be recognized automatically

5351 338 v1.8

124
 Additional information

Wiring Diagrams

Overview

A2 Low-voltage motherboard
A3 Line voltage motherboard
A6 Programming unit
A7 Optolink/override switch board
A8 Electronics board
A9 Boiler coding card
A10 LON communication module or
Viessmann 2-wire BUS
communication module
A11 Power supply unit board
A12 Boiler control section
5351 338 v1.8

125
Additional information

Wiring Diagrams (continued)

Low-voltage motherboard

34--pole
A11
A8

A9
A6

A2
A7

A10

5351 338 v1.8

126
 Additional information

Wiring Diagrams (continued)

Low-voltage motherboard (continued)

§ Boiler temperature sensor aJA Temperature sensor T1 S3 Override switch ”S”

% Tank temperature sensor aJB Temperature sensor T2 V1 Fault indicator (red)
(accessory) aVD Connection of external V2 Operating status indicator (green)
aG Flue gas temperature sensor equipment
(accessory) aVG KM BUS participant (accessory)
aVH Connection of external
equipment
LON Connecting cable for data
transfer between the control
units
5351 338 v1.8

127
Additional information

Wiring Diagrams (continued)

Line voltage motherboard

floating

ON ON
A11

A3

5351 338 v1.8

128
 Additional information

Wiring Diagrams (continued)

Line voltage motherboard (continued)

sÖ Control output lÖ Burner (2nd stage/modulating) F1, F2 Fuses

sA DHW pump aBÖ External equipment F6 Fixed high limit ”E”
sL Shunt pump or boiler circuit pump a External safety equipment 120°C (99°C or 110°C) /
fÖ Power supply connection, (remove jumper when 248°F (210°C or 230°F)
120 VAC connecting) F7 adjustable high limit ”R”
fA Burner connection b External controlled switch-off 95°C (100°C or 110°C)
gÖ Compiled failure alarm (remove jumper when 203°F (212°F or 230°F)
gS Boiler isolation valve connecting) K1-K10 Relay
or c External burner activation S1 Heating system on/off
Boiler return valve aBA Safety circuit - emergency switch ”8”
shut-off S2 TUV button
aBH Power supply connection for
accessories
5351 338 v1.8

129
Additional information

Parts List

GC1 Series
Order No. Serial No. *1
7134 553, 7134 554, 7511 361 7143003
7187096
7248247

Ordering Replacement Parts:

Please provide product Model and
Serial Number from rating plate when
ordering replacement parts. Order
replacement parts from your
Viessmann distributor.

Parts
001 Hinges 050 Circuit board (control software) Other Parts (not illustrated)
002 Optic link 051 Diagnostics module (Optolink) 060 Accessory pack (plugs)
004 Adjustable high limit knob 052 Motherboard 061 Coding plug for Vitocrossal 200
005 Fixed high limit cover (control, line voltage) 062 Coding plug for Vitorond 200
006 Dial-stop 110°C / 230°F 054 Circuit board 063 Coding plug for Vitocrossal 300;
008 Support arm (120V power supply) nnn
011 Safety module (wired) 055 Communication module, 080 Installation / Service Instructions
013 Front housing (with Pos. 001) 2-wire BUS Vitotronic 100, GC1
014 Circuit board enclosure 056 LON module 081 Operating Instructions
015 Flip-down cover 065 Burner cable Nr. 41/90 l=3470 Vitotronic 100, GC1
016 Rear housing 067 Sensor (immersion, NI500) 082 Parts List Vitotronic 100, GC1
018 Programming unit 068 Sensor #2 for supply Rating plate
024 Fuse holder cover 074 Harness for programming unit
025 Fuse holder 092 Fuse 6.3A / 250V (10 pack) *1 A 16-digit bar-coded serial no.
030 Fixed high limit is printed on the front housing,
031 Adjustable high limit below the flip-down cover.
037 Switch, 1-pole (FHL test)
038 Switch, 2-pole (power on/off)
042 Sensor #3 for boiler
043 Sensor #5 for domestic hot
water production
049 Motherboard
(control, low voltage)

5351 338 v1.8

130
 Additional information

Parts List
5351 338 v1.8

131
Additional information

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5351 338 v1.8

Viessmann Manufacturing Company (U.S.) Inc. Viessmann Manufacturing Company Inc.

45 Access Road 750 McMurray Road
Warwick, Rhode Island • 02886 • USA Waterloo, Ontario • N2V 2G5 • Canada
Tel. (401) 732-0667 • Fax (401) 732-0590 Tel. (519) 885-6300 • Fax (519) 885-0887
www.viessmann-us.com • info@viessmann-us.com www.viessmann.ca • info@viessmann.ca
132