Chofu

Commissioning Guide
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Commissioning Guide
This document must be read in association with the Chofu Installation Manual provided with the unit. It is essential the
manual is read and followed to ensure the installation is as per manufacturer’s criteria. The purpose of this document
is to assist with the commissioning of the heat pump parameters and the connection of third party controls.

Contents

Pre-Commissioning
Pre-Commissioning Checks ........................................................................................................................................................................................ 4
Filling the System with Water ..................................................................................................................................................................................... 4
Heat Pump Controller .................................................................................................................................................................................................... 5

Room Thermostat Connection

Room Thermostat Connection .................................................................................................................................................................................. 6
Heating and Cooling Changeover ............................................................................................................................................................................ 6

Heat Pump Controller Settings

Heat Pump Controller Settings .................................................................................................................................................................................. 7

Heating Only System Configurations

System 1: Heat Pump Switched On/Off by Room Thermostat(s) Heating Only .................................................................................... 8
System 2: Heat Pump Switched On/Off by Room Thermostat(s), Heating Only + DHW.................................................................... 9

Heating & Cooling System Configurations

Selecting The Correct Cooling Option ..................................................................................................................................................................10
System 3-A: Heat Pump Switched On/Off by Room Thermostat(s) Heating & Type A Cooling ....................................................11
System 3-B: Heat Pump Switched On/Off by Room Thermostat(s) Heating & Type B Cooling ..............................................12-13
System 4-A: Heat Pump Switched On/Off by Room Thermostat(s), Heating & Type A Cooling + DHW.............................14-15
System 4-B: Heat Pump Switched On/Off by Room Thermostat(s), Heating & Type B Cooling + DHW..............................16-17

System Operational Checks

Checking Sensor Values ..............................................................................................................................................................................................18

Resetting Errors
Resetting Errors...............................................................................................................................................................................................................19

Additional Information
Additional Information................................................................................................................................................................................................19

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 Pre-Commissioning
Pre-Commissioning Checks
Prior to Filling with water
A: Ensure the heat pump is installed in accordance with the installation manual.
B: Ensure the power is isolated to the unit.
C: Remove the side cover of the unit to expose the water pump, compressor and electrical enclosure.
D: Check the pre-charge of the expansion vessel is set to 1 bar.

Filling the System with Water

Thoroughly flush the system with a flushing cart or suitable mains pressure, until there is no sign of air returning
through the primary feed pipes. This will remove most of the air from the system. Now pressurise the system to
1 Bar on the heat pumps pressure gauge. The heat pump has a pump run switch on the terminal PCB under the
side cover of the heat pump. This allows the circulation pump to be run manually to help fully vent the system
of air. Ensure the automatic air vents in the system are open.

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Heat Pump Controller (connection)
The Chofu heat pump controller must be installed to manage the heat pump operation. The controller is not rated
for outdoor use, installation indoors in a dry place is recommended; i.e. garage or service cupboard.

Terminal #1 and #2.

Low voltage, not polarity sensitive.
DO NOT APPLY 230V TO THESE TERMINALS.

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 Room Thermostat
Connection (remote contact)
Connect room thermostat wiring to terminals #20, #21 via the normally open contacts of the room thermostat.
The thermostat requires volt free contacts to open/close terminals #20, #21. If the thermostat features a switched
live output for on/off, an external relay with volt free contacts will need to be used. Open contacts = Off;
Closed contacts = On. These terminals are enabled when changing parameter 5120. See system configuration
for more details.
Low voltage, not polarity sensitive.
DO NOT APPLY 230V TO THESE TERMINALS.

Low voltage, not polarity sensitive.

DO NOT APPLY 230V TO THESE TERMINALS.

Heating and Cooling

changeover
If your room thermostat has heating and cooling functionality it can change the operating mode of the heat
pump. Connect the thermostat changeover wiring to terminals #24, #25 via the normally open contacts of the
room thermostat. The thermostat requires volt free contacts to open/close terminals #24, #25. If the thermostat
features a switched live output for changeover, an external relay with volt free contacts will need to be used.
Open contacts = Heating; Closed contacts = Cooling. These terminals are enabled when changing parameter 5124.
See system configuration for more details.

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 Heat Pump
Controller Settings
The heat pump controller must be installed to manage and configure control parameters.

For install level

1. For Install parameters hold down the 3 buttons
together for 3 seconds.
2. The parameter number (4 digits) will be displayed,
and the value of the parameter. (2 of the 4 parameter
digits will be flashing).
3. Change these (flashing) numbers using the Up/Down
buttons, or
4. Change to the other 2 digits using the +/– buttons,
or and changes these too if necessary.
5. Press the Set button
6. The parameter value will now flash.
7. Change value using the or buttons.
8. Press the Set button to confirm the new value.
9. To default back to the main menu, press together for
3 seconds. The controller will default back to the main menu screen.

For service level

1. Press the Menu, and buttons simultaneously for 3 seconds. The INSTALLER level setting menu
will be displayed.

1. Enter the password to access the SERVICE level, specify parameter number “9999” and enter password
“738”, and press the Set button to confirm entry of the password.

1. “SErv” (means SERVICE) will be displayed in the position of room temperature display. In SERVICE level,
all parameters can be accessed. The procedures of setting parameters are same as INSTALLER level.

2. To return to normal operation, press and hold the Menu, and

for 3 seconds, or simply do nothing for approximately 10 minutes.

Procedure for resetting parameters

In SERVICE level, all parameters can be
reset to the default when the LOW tariff/
Night mode button is pressed and held
for 10 seconds.
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 System Configuration
The following is a list of common configurations that are typically used. If you require something specific to your
installation please contact us for a tailored list of parameters.

System 1: Heat Pump Switched On/Off by Room Thermostat(s) Heating Only

System 2: Heat Pump Switched On/Off by Room Thermostat(s) Heating + DHW
System 3: Heat Pump Switched On/Off by Room Thermostat(s) Heating & Cooling
System 4: Heat Pump Switched On/Off by Room Thermostat(s) Heating & Cooling + DHW

System 1: Heat Pump Switched On/Off by Room

Thermostat(s) Heating Only

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

4301 Start temp of frost protection on room air temperature 14 5

Terminal 20-21: On/Off remote contact or EHS Alarm input

0 = Disable (Remote controller only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable

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System 2: Heat Pump Switched On/Off by Room
Thermostat(s) Heating + DHW

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

0 = DHW is unavailable
3101 0 1
1 = DHW is available, and priority DHW over space heating

3111 DHW set temperature (of water in cylinder) 50 50

4301 Start temp of frost protection on room air temperature 14 5

Enable DHW sensor: Terminal 7-8

5107 0 = Disable 0 1
1 = Enable

Terminal 20-21: On/Off remote contact or EHS Alarm input

0 = Disable (Remote controller only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable

Enable DHW 3-way valve: Terminal 50-51-52

5150 0 = Disable 0 1
1 = Enable

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 Selecting The Correct
Cooling Option
The following system configurations are for systems that provide both heating and cooling. Depending on the
type of cooling system or part of the country the home is in, the cooling settings need to be selected to ensure
they are suitable.
The following system types are 3-A & 3-B for heating and cooling without domestic hot water heating & 4-A & 4-B
for heating and cooling with domestic hot water heating. The A & B of these systems are the different cooling
set points which are explained further below.

A – Cooling settings: Fixed or weather compensated

set point
These settings are optimal for systems that suit lower chilled water temperatures and where condensation
is not as much of a concern, the examples for this are:
• Fan coil systems where condensation is removed via condensate drains.
• In slab underfloor cooling systems in regions of lower summer humidity levels – typically this is the South Island
region.
• These settings will maximise cooling performance over efficiency and suit situations where this is the most
important factor.

B – Cooling settings: Weather compensated set point

with humidity compensation
These settings are suitable for systems that need to have weather and humidity compensated flow temperatures
to improve efficiency and/or reduce the risk of the formation of condensation, the examples for this are:
• Variotherm Variocomp or Module panel radiant cooling systems.
• In slab underfloor cooling systems in regions of higher summer humidity levels – typically this applies to the
North Island region.
• These settings will maximise cooling efficiency over performance and suit systems where this is the most
important factor.

Note: For radiant cooling systems the CHNZ SmartOne thermostat must be used with the
dew point check function enabled. The floor probe must be installed in conduit in the floor
slab for an underfloor heating system or securely attached and insulated to a return pipe on
a Variocomp/Modulepanel system.

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System 3-A: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type A Cooling

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

Cooling, enable outgoing water set point

See
2120 0 = Fixed set point for fan coils 0
description
1 = Climatic curve enabled for underfloor

2122 Maximum outgoing water temperature in Cooling mode 20 15

2123 Minimum outgoing water temperature in Cooling mode 18 10

Minimum outdoor air temperature corresponding to maximum

2124 25 20
Outgoing water temperature

Maximum outdoor air temperature corresponding to maximum

2125 35 30
Outgoing water temperature

4301 Start temperature of frost protection on room air temperature 14 5

Terminal 20-21: On/Off remote contact or EHS Alarm input

0 = Disable (Remote controller only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Terminal 24-25: Heating/Cooling mode remote contact

0 = Disable (Remote Controller Only)
5124 0 1
1 = Cooling is CLOSE contact, Heating is OPEN contact
2 = Cooling is OPEN contact, Heating is CLOSE contact

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable

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 System 3-B: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type B Cooling

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

Cooling, enable outgoing water set point

2120 0 = Fixed set point 0 1
1 = Climatic curve enabled

2122 Maximum outgoing water temperature in Cooling mode 20 15

2123 Minimum outgoing water temperature in Cooling mode 18 10

Minimum outdoor air temperature corresponding to maximum

2124 25 20
Outgoing water temperature

Maximum outdoor air temperature corresponding to maximum

2125 35 30
Outgoing water temperature

4301 Start temperature of frost protection on room air temperature 14 5

Terminal 17-18: Humidity sensor

5117 0 = Disable 0 1
1 = Enabled

System 3-B continues on the next page

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System 3-B: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type B Cooling continued

Value
Parameter Description
Default Set To

Terminal 20-21: On/Off remote contact or EHS Alarm input

0 = Disable (Remote Controller Only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Terminal 24-25: Heating/Cooling mode remote contact

0 = Disable (Remote Controller Only)
5124 0 1
1 = Cooling is CLOSE contact, Heating is OPEN contact
2 = Cooling is OPEN contact, Heating is CLOSE contact

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable

Note: While setting up this system and the thermostat, the 0-10V output from the thermostat will
drop on and off causing an L5 error on the heat pump. While this may not clear immediately, after
a few minutes the fault can be reset and heat pump operation will resume.

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 System 4-A: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type A Cooling + DHW

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

Cooling, enable outgoing water set point

See
2120 0 = Fixed set point for fan coils 0
description
1 = Climatic curve enabled for underfloor

2122 Maximum outgoing water temperature in Cooling mode 20 15

2123 Minimum outgoing water temperature in Cooling mode 18 10

Minimum outdoor air temperature corresponding to maximum

2124 25 20
Outgoing water temperature

Maximum outdoor air temperature corresponding to maximum

2125 35 30
Outgoing water temperature

0 = DHW is available
3101 0 1
1 = DHW is available, and priority DHW over space heating

3111 DHW set temperature (of water in cylinder) 50 50

4301 Start temperature of frost protection on room air temperature 14 5

Enable DHW sensor: Terminal 7-8

5107 0 = Disable 0 1
1 = Enable

System 4-A continues on the next page

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System 4-A: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type A Cooling + DHW continued

Value
Parameter Description
Default Set To

Terminal 20-21: On/Off remote contact or EHS Alarm input

0 = Disable (Remote controller only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Terminal 24-25: Heating/Cooling mode remote contact

0 = Disable (Remote Controller Only)
5124 0 1
1 = Cooling is CLOSE contact, Heating is OPEN contact
2 = Cooling is OPEN contact, Heating is CLOSE contact

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable

Enable DHW 3-way valve: Terminal 50-51-52

5150 0 = Disable 0 1
1 = Enable

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 System 4-B: Heat Pump Switched On/Off by Room
Thermostat(s) Heating & Type B Cooling + DHW

Value
Parameter Description
Default Set To

Flow temperature set point for heating

See
2101 35 to 45 underfloor (depending on floor covering) 45
description
60 – radiators

Cooling, enable outgoing water set point

2120 0 = Fixed set point 0 1
1 = Climatic curve enabled

2122 Maximum outgoing water temperature in Cooling mode 20 15

2123 Minimum outgoing water temperature in Cooling mode 18 10

Minimum outdoor air temperature corresponding to maximum

2124 25 20
Outgoing water temperature

Maximum outdoor air temperature corresponding to maximum

2125 35 30
Outgoing water temperature

0 = DHW is available
3101 0 1
1 = DHW is available, and priority DHW over space heating

3111 DHW set temperature (of water in cylinder) 50 50

4301 Start temperature of frost protection on room air temperature 14 5

System 4-B continues on the next page

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System 4-B: Heat Pump Switched On/Off by
Room Thermostat(s) Heating & Type B Cooling
+ DHW continued

Value
Parameter Description
Default Set To
Enable DHW sensor: Terminal 7-8
5107 0 = Disable 0 1
1 = Enable
Terminal 17-18: Humidity sensor
5117 0 = Disable 0 1
1 = Enable
Terminal 20-21: On/Off remote contact or EHS Alarm input
0 = Disable (Remote controller only)
5120 0 1
1 = On/Off remote contact
2 = EHS Alarm input

Terminal 24-25: Heating/Cooling mode remote contact

0 = Disable (Remote Controller Only)
5124 0 1
1 = Cooling is CLOSE contact, Heating is OPEN contact
2 = Cooling is OPEN contact, Heating is CLOSE contact

Flow switch input, terminals 26-27:

5126 0 = Disable 1 0
1 = Enable
Enable DHW 3-way valve: Terminal 50-51-52
5150 0 = Disable 0 1
1 = Enable

Note: While setting up this system and the thermostat, the 0-10V output from the thermostat will
drop on and off causing an L5 error on the heat pump. While this may not clear immediately, after
a few minutes the fault can be reset and heat pump operation will resume.

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 System Operational Checks
Once the heat pump is set up, it is a very good idea to check that everything works as intended and that
the heat pump starts and stops when it should in response to the controls used, and there is a good flow rate
at the manifolds and radiators get hot.

Checking Sensor Values

Ensure these temperatures are recorded when the heat pump is running steadily.

Parameter Function Description Display Unit

01 00 Return water temperature 1°C
01 09 Flow water temperature 1°C
01 06 Outdoor air temperature 1°C
01 31 DHW sensor temperature 1°C

Alternatively these can be viewed from the outdoor units terminal PCB.

PCB(Terminal) Pump SW.

Dip SW4 = ON Display on PCB (Terminal) display

ON
OFF • Turn On the dip SW4 on the PCB (Terminal) to display
the monitor number and monitor data alternately.
number monitor data
alternately • Push the Pump SW, of the PCB (Terminal) to switch
the display number alternately.
Pump SW.
change number • To return to normal display, turn Off the Dip SW4.

Number Parameter Default Minimum Maximum Unit

d0 01 00 Circulating warm return temperature - -20 100 1°C
d1 01 01 Compressor operating frequency - 0 200 1Hz
d2 01 02 Discharge temperature - -20 150 1°C
d3 01 03 Current consumption value - 0 9900 100W
d4 01 04 Fan control number of rotation - 0 1000 10rpm
d5 01 05 Defrost temperature - -20 100 1°C
d6 01 06 Outdoor air temperature - -20 100 1°C
d7 01 07 Water pump control number of rotation - 0 9900 100rpm
d8 01 08 Suction temperature - -20 100 1°C
d9 01 09 Circulating water outgoing temperature - -20 100 1°C

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Additional Settings

If an excessive flow rate occurs due to low pressure loss of the circulating loop, adjust the Main water pump
speed so that the flow rate is reduced.

Using the Dip switches on the PCB (Terminal) – as noted on the above diagram, 3-Pump speeds are available.

Be aware that an excessively low flow rate may cause problems including diminished capacity, poor circulation, or
system errors.

At the factory shipment, both SW5 and SW6 are Off, which means the pump will operate at maximum.

Resetting Errors
The procedure to reset the error display differs between error codes and there are 3 ways to reset: Auto, Power Off,
and Manual. See “List of Errors codes” in the Chofu installation manual for the procedure to reset each error code.

Auto: Automatically. Once it returns to normal condition, the error will be reset. When the unit stops, it may
not be possible to reset automatically. Then, it needs to be reset manually.
Power Off: Manually. If Heat pump unit returns to normal condition, turn Off the power supply once and turn On
again, then the error will be reset.
Manual: Manually. To reset the error, press – and + button of the Master Remote controller at the same time for
3 seconds, or press Reset SW on the PCB (Terminal).

If the error persists please contact our technical aftersales team for assistance with the fault:
aftersalestechnical@centralheating.co.nz or call 0800 357 1233

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