HOUNÖ

SERVICE MANUAL - English

B, C & K Visual Cooking Models (Gas & Electric)

Software Version 3.51 - 04 /2019

CAUTION: Read these instructions before servicing the oven

TABLE OF CONTENTS

Introduction 5

Utility Connections 6

Standards and codes 7

Important Safety Information 8

Safety Instructions 9

Operation panel 11

Settings 12

Description of Functions 15

Hot Air 15

Menu table 21

Setup menu 22

User menu 24
TEST Menu 27

Cleaning 35

Water layout 38

I/O board led 40

Frequency inverter 41

Error Codes 42

Troubleshooting ERROR CODES 44

2 SERVICE MANUAL REVISION 04/19, SW: 3.51

 TABLE OF CONTENTS

GAS Burner Electrode Adjustments 62

Gas Pressure 64

Gas Burner Settings 65

Changing type of gas 68

Switch adjustment 69

Gas Sequence Diagram 70

Gas Components 71

Identifying parts 74

Error codes on Dungs’ Control Box 75

PT 100 table 79

SERVICE AND REPAIR 80

Safety 80
warranty 80

REVISION 04/19, SW: 3.51 SERVICE MANUAL 3



4 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Introduction

INTRODUCTION
Dear technician,
This service manual contains all the information you need to service and maintain a
Visual Cooking combi oven from HOUNÖ.
We recommend that you read both the manual and familiarize yourself with the service
settings and functions of the oven. This will ensure optimal cooking and baking results
and safety.
Please make the manual available to all who service and maintain the oven and retain it
for future reference.
The latest version of the manual can be downloaded from www.houno.com.
Note that this document is subject to change without notice.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 5

 Utility Connections

IMPORTANT
WARNING: Improper
installation, adjustment,
UTILITY CONNECTIONS
alternation, service or
maintenance can cause
THE SERVICE INSTRUCTIONS CONTAINED HEREIN ARE FOR THE USE OF QUALIFIED
property damage, injury
INSTALLATION AND SERVICE PERSONNEL ONLY. INSTALLATION OR SERVICE BY OTHER
or death. Read the
THAN QUALIFIED PERSONNEL MAY RESULT IN DAMAGE TO THE OVEN AND/OR INJURY
installation, operation
TO THE OPERATOR.
and maintenance
instructions
thoroughly before
Qualified service/installation personnel are individuals, a firm, a corporation, or a
installing or servicing this
company, which either in person or through a representative are engaged in, and
equipment.
responsible for:
INSTRUCTIONS TO
BE FOLLOWED IN THE • The service/installation or replacement of gas piping and the connection, instal-
EVENT THE USER lation, repair or servicing of equipment.
SMELLS GAS MUST
• The installation, repair or service of electrical wiring from the electric meter,
BE POSTED IN A
main control box or service outlet to the electric appliance.
PROMINENT LOCATION.
This information may be • Qualified installation/service personnel must be experienced in such work,
obtained by contacting familiar with all precautions required, and have complied with all requirements of
your local gas supplier. state or local authorities having jurisdiction.
FOR YOUR SAFETY
Do not store or use
gasoline or other
flammable vapors or
liquids in the vicinity
of this or any other
appliance.
The information
contained in this manual
is important for the
proper installation, use,
and maintenance of
this oven. Adherence to
these procedures and
instructions will result
in satisfactory baking
results and long, trouble
free service. Please read
this manual carefully
and retain it for future
reference.
ERRORS: Descriptive,
typographic or pictorial
errors are subject to
correction. Specifica-
tions are subject to
change without notice.

6 SERVICE MANUAL REVISION 04/19, SW: 3.51

Standards and codes

STANDARDS
AND CODES
U.S. and Canadian installations

The installation must conform with local codes, or in the absence of local codes, with
the National Fuel Gas Code, ANSI Z223.1/NFPA 54, or the Natural Gas and Propane
Installation/service Code, CSA B149.1, as applicable.

Installation/service must conform with local codes, or in the absence of local codes, with
the National Electrical Code, ANSI/NFPA 70-Latest Edition and/or Canadian National
Electric Code C22.1 as applicable.

Appliance is to be installed with back flow prevention in accordance with applicable

federal, province and local codes.

Australia and general export installations

Installation must conform with Local and National installation standards. Local
installation codes and/or requirements may vary. If you have any questions regarding
the proper installation, service, repair and/or operation of your HOUNÖ oven, please
contact your local distributor. If you do not have a local distributor, please call the
HOUNÖ Oven Company at +45 87 11 47 11.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 7

Important Safety Information

IMPORTANT SAFETY
INFORMATION
The following icons are used throughout this manual to draw special attention to safety
related information.

The service personnel should observe and/or act according to the

infomation in order to obtain the best possible function of the oven.

The service personnel must observe and/or act according to the

information in order to avoid any personal injury or damage to the
oven.

The service personnel must observe and/or act according to the

information in order to avoid any fatal injury. The symbol indicates a
hazard arising from dangerous voltage.

8 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Safety Instructions

SAFETY INSTRUCTIONS
Ready for use
When the oven has been correctly installed, please read this manual carefully before
the oven comes into service.
Please make the manual available to all who service and maintain the oven and retain it
for future reference.
Always place trays filled with hot liquid in the bottom runners of the oven chamber to
avoid spilling the hot liquid on yourself when you take the tray out of the oven chamber.
Some areas on the outside of the oven may get as hot as 60°C or more. Therefore, you
should only touch the front of the oven.
Do not open the oven during the automatic cleaning process.
Do not store flammable materials around or under the unit.
When using the roll-in or trolley system, be aware of hot racks sliding out of the oven.
Use the parking brakes on the wheels to prevent trolleys from rolling away on uneven
floors.

Gas units only

All gas units must be installed under an extraction hood, that is switched on when the
oven is working.
Do not block the exhaust pipes or the area around the oven.
The oven should only be used in calm conditions.

Failure to comply with the above instructions may increase the risk of
fire!

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Safety Instructions

If you smell gas….

• Turn off the gas supply immediately.
• Do not use the control panel.
• Make sure there is ample ventilation near the oven.
• Avoid open fire and sparks.
• Call the gas supplier, using an external phone.

Maintenance and repair

Maintenance and repair should only be carried out by trained technicians.
Only use cleaning detergent that matches the specifications from the factory.

10 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Operation panel

OPERATION PANEL
TEMPERATURE SETTING. Press Main switch HOT AIR 30-250°C. All modes
once and set the temperature and all optional extras are
with TURN SWITCH. Enter by described on the following
pressing the symbol again. pages. aPreheating up to
300°C is a standard feature on
models C and K.
TIME SETTING. Press once and
set time with TURN SWITCH.
Four hours are maximum. REGENERATING / COMBI
Confirm by pressing TIME. STEAMING
Change between the modes by
pressing
SETTING CORE TEMP. PROBE PROVING
(optional extra). Press once REGENERATING
and set with TURN SWITCH. COMBISMART.
Deactivate by turning the
switch past the permitted temp.
range of 30-99°C. STEAMING 30-120°C (2). Used
for manual humidity pulsing in
HOT AIR during preparation.
PROGRAMMES. Press once and
choose the program with TURN
SWITCH. Editing and deleting DAMPER is open when the
are described on page 13. control lamp is on.
Setting of the humidity level in
CombiSmart
When the control lamp is on,
STEP shows current step when changes have been made.
PROGRAMME mode is active.
The control lamp next to
ALARM lights up when the Setting of FAN SPEED
alarm after a step has been When the control lamp is on,
chosen (when PRG is active). On/off Turn switch changes have been made.

(1) If the oven does not incorporate CombiWash, the manually operated cleaning
system can be activated by pressing the programmes key and turning the turn
knob until CLEANING appears in the display.
(2) The C model has no steam generator, but this mode makes it possible to steam in
the oven anyway. At temperatures between 65 and 100°C, you can steam all kinds
of vegetables, rice, pasta, meat and fish.

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Settings

SETTINGS
Setting of temperature
1. Press TEMPERATURE once and set the temperature with the turn knob.
2. Confirm by pressing TEMPERATURE again.

Setting of time
1. Press TIME. The time flashes.
2. Choose the desired time (hours and minutes) with the turn knob.
3. If the knob is turned all the way down to 0,”-:--” (continuous operation) appears in
the display.
4. Maximum time setting is four hours.
5. Confirm by pressing TIME again.

Setting of core temperature

(optional extra)
1. Press CORE TEMPERATURE.
2. If the display is off, the core temperature appears as 75°C.
3. Set the core temperature between 30 and 99°C with the turn knob.
4. The core temperature is deactivated by turning the knob past 30.
5. When the core temperature is chosen, the time changes to ”-:--” .
6. Confirm by pressing CORE TEMPERATURE again. The core temperature probe
has three measuring points on its tip.
If the probe is inserted incorrectly, the advanced technology notifies you at once.
The probe is inserted vertically in the thickest part of the product.
When preparing products of very different sizes, you get a uniform quality by inserting
the sensor in the smallest product and then moving it to a larger product when the core
temperature alarm sounds.

12 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Settings

Programmes
50 programmes holding ten process steps each. It is possible to write ten characters
and enter an alarm after steps 1 and 2.
1. Press the programmes key and turn the knob.
2. Start the programme by pressing the ON/OFF key.
3. To leave PROGRAMME, turn the knob beyond ”P O”.
4. To delete an entire programme, press the core temperature key and alarm key
simultaneously for two seconds.
When the keys or the turn knob is idle for 20 seconds, the oven returns to manual
operation.

Entering and changing text

1. To enter or change text, press the programmes key for three seconds.
2. The first digit or the relevant letter/”_” flashes alternately. Change the flashing
character with the turn knob. You can choose between all the letters of the
alphabet and the digits 0 – 9.
3. The space sign is next to the letter A.
4. Move on to the next digit by pressing briefly.
5. Store text by pressing until “SAVED” appears in the display. To leave text
editing without storing, press ALARM. The original text reappears.
6. To delete the entire text, press the programmes key and ALARM simultane-
ously for two seconds.
When a key or the turn knob is idle for 20 seconds, the oven returns to select
programme.

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Settings

Entering and changing data in steps

By pressing STEP when PROGRAMME is active, the step display is turned on and shows
”1”. The data of the first step can now be entered.
To move on to the next step (1-10) and read and change settings, press STEP again.
Choose and change temperature, time, core temperature, damper and fan as in manual
operation.
Stop between steps: To turn the alarm between steps on and off, press ALARM. If the
control lamp is on, the programme ends with the current step and a beep is heard. The
oven does not proceed to the next step until the oven door is opened and closed or you
press ALARM.
To store a change made in the step mode, press the programmes key for 2 seconds.
Leave STEP by choosing another programme with the turn knob.

Be careful not to use the turn knob when a value flashes. If you
turn the knob while you are working in STEPS, the computer
switches to the next programme and all changes are lost.

Delete the current step by pressing STEP and ALARM simultaneously for two seconds.
When the programme has started, you can still change time, temperature, core temper-
ature and the settings of fan and damper. These changes will then only be active in the
current run. Note that the display shows the total time remaining after start and that it
will show the time remaining in the current step when you press TIME.

14 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Description of Functions

DESCRIPTION OF
FUNCTIONS
Hot Air
30-250°C
The hot air operating mode can be used for roasting, grilling, baking and gratinating.
We recommend that you keep the damper open when roasting products at very high
temperatures. It is possible to roast breaded products such as breaded fish and breaded
pork chops.
If you wish to cook at temperatures below 80°C, the fan speed should be reduced to
below 50%

Preheating
251-300°C
By setting the temperature higher than 250°C, you change to the preheating mode
and PREHEAT is shown instead of HOT AIR. With this function, you preheat the empty
oven. The time can be set to maximum 15 minutes, and continuous operation (-:--)
is not possible. The preheating mode has been changed so that the countdown does
not start until the desired temperature has been reached. This is to ensure that the
oven is always in the same condition when the oven is loaded, no matter the starting
temperature.

It is recommended to always preheat the oven before use.

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Description of Functions

CombiSmart
30-250°C
CombiSmart is a function for humidity control which allows you to adjust the humidity
level in 10 steps (10-100). Press the damper key and adjust the level by turning the turn
knob. Confirm the setting by pressing the damper key again. The control lamp next to
the damper key will be on. In this function, the damper is usually closed, however, at the
setting 0 the damper opens.
Settings 20-50 are recommended for the production of whole roasts. The humidity
helps to seal the surface and keep the juice in the meat, which reduces shrinkage. These
settings are also recommended for the preparation of root vegetables and the like.
Settings 60-90 are recommended for the production of braised roasts for which
you want to use the juice in the container for gravy. The amount of liquid in the tray
increases during production. These settings are often recommended for roasts that
should be well-done, to keep some of the juice in the meat.

Cook & Regen

30–180°C
COOK & REGEN is a very gentle process and therefore very suitable for reheating. Use
a core temperature probe to reach the perfect end temperature. For the reheating of
sous-vide products, etc., follow the recommendations of the producer as to reheating.
The products should not be covered up as this impedes optimum and quick reheating.

Proving
30-40°C
PROVING is a function for raising bread by adding humidity at temperatures between 30
and 40°C. These are optimum conditions for the yeast to expand.

16 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Description of Functions

Manual humidity pulsing

When you press the key for STEAMING in the HOT AIR mode, you add humidity to the
oven chamber. Humidity is added for as long as the key is held down.

Steaming in a C model
30-120°C
Can be used for steaming of all types of vegetables, pasta, rice, meat, eggs and the like.
If the oven chamber is 100% loaded with frozen products, hard root vegetables or meat,
it will take a little longer until the oven chamber is completely filled with humidity, and
the preparation time will be longer than if the oven chamber is only half full.

Steaming in a K model
When the steam generator is cold (< 65°), the steaming starts with a flushing of the
generator. It takes approximately 8 minutes before the oven produces steam (the
change of water only takes place when the temperature in the steam generator is below
65°C).
The steam generator is then hot and steam is generated immediately.

General recommendations for steaming

STEAMING at 100°C is recommended for all kinds of hard vegetables, rice and pasta.
LOW-TEMPERATURE STEAMING at 70-80°C is recommended for the steaming of fish.
FORCED STEAMING at 120°C is an aggressive and very rapid process, which should be
used with care.
IT IS RECOMMENDED TO LET THE OVEN PRESTEAM FOR 8 MINUTES BEFORE LOADING
IT. THIS APPLIES TO THE C MODEL AS WELL AS to the K MODEL.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 17

Description of Functions

Damper
The damper is usually closed in all operating modes. When the control lamp is on, the
damper is open.
NOTE! In CombiSmart, this key is used for adjusting the humidity level.
The damper is always closed in the steaming mode.
If you wish to reduce the amount of humidity in the oven chamber – when you brown, for
instance – the damper should be open.

Fan speed
Set the fan speed by pressing the fan key and turn the knob.
A fan speed between 20 and 50% is recommended for the baking of puff pastry, Danish
pastry, cakes and small products as well as in the Delta-T and Cook-and-Hold modes.
You may add 1-2 minutes’ preparation time for each hour when low fan speed is used.
Fan speeds below 50% cannot be used at temperatures above 200°C.
A fan speed between 50 and 100% is recommended if you want a particularly juicy end
product and accept a longer cooking time.

Hours, date and setting of timer

Shows the exact time and date when the oven is off. For setting of clock and timer, see
USER MENU on page 28.

18 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Description of Functions

Fully automatic cleaning system,

CombiWash (optional extra)
The cleaning system should be used every day. You choose between levels 1, 2, 3 and 4
and possibly additional detergent, depending on how soiled the oven chamber is. The
last thing you do before turning off the light in the evening is activating CombiWash.
When CombiWash is finished, the computer automatically switches to an energy-saving
standby function.
Follow these steps to start CombiWash:
1. Cool down the oven chamber to 80°C.
2. Check the level of detergent and rinse aid.
3. Press the programmes key and turn the knob until CombiWash appears in
the display.
4. Press STEP to select cleaning level: 0 is 2 minutes’ flushing with water – 1 is light
cleaning and 4 is very thorough cleaning.
5. Close the oven door and press ON.
6. Select the desired cleaning mode. You can choose between the following cleaning
cycles.
• 0 - Flush: Use this before starting the other cleaning programmes.
• 1 - Light: Use this after steaming and roasting at low temperatures.
• 2 - Medium: Use this after steaming and roasting at medium temperatures.
• 3 - Heavy: Use this after roasting at temperatures higher than 180°C.
• 4 - Intensive: Use this after roasting very greasy products.

Note: If the cleaning cycle is interrupted before it has been completed, for example
because of a power outage, the oven automatically performs a safety flush to remove
any detergent remnants.
We recommend that the oven is cleaned on a daily basis or after each production.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 19

Description of Functions

Semi-automatic cleaning
This function is for ovens without CombiWash.
1. Cool down oven chamber to 60°C.
2. Press the programmes key and cleaning appears in the display. Press ON.
3. When the alarm sounds (after 10 minutes) and add soap appears in the display,
open the oven door and spray HOUNO detergent into oven chamber. Close the
oven door and the programme continues.
4. When the programme is over, rinse oven appears in the display (after another
10 minutes). Rinse the oven chamber.
If the oven is very soiled, activate combi steaming 2 at 80°C for 30 minutes before
starting cleaning programme.

NOTE: Oven damage due to the lack of regular cleaning with HOUNÖ
PROTECT Detergent Intense and Rinse Aid may render the warranty
void!

NOTE: Oven damage due to the absence of a necessary HOUNÖ

PROTECT HydroShield water filter may render the warranty void!

20 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Menu table

MENU TABLE
USER MENU: To enter the User menu, hold the BELL button for 5 seconds and the
core-probe line of the display will show B 1.
SET UP MENU: To enter the SET UP menu, hold the HOT AIR and STEAM buttons for 5
seconds and the core probe line of the display will show U 1.
TEST MENU: To enter the test menu, hold the HOT AIR and COMBI buttons for 5
seconds and the core probe line of the display will show U 1.

USER MENU SETUP MENU TEST MENU

0 Main Contactor
1 Save default Oven type (B_C_K) Heating
2 Timer start Oven size Generator heating
3 Sound low CombiWash Fan right
4 Sound high Temperatur 0=C 1=F Fan left
5 Sound frequency Gas
6 Light Low temp steaming Injection steam function
7 Actual temperature Preheat 300°C Filling valve
8 Extraction Water level set Empty pump
9 Time/graph Restart after power cut Drain cooling
10 Minute Damper motor
11 Hour Core probe Extraction
12 Date/weekday Drain cooling Cooling fan
13 Month Timer start Test sound
14 Year Demo mode Light
15 Initialise Oven temperature
16 Gas RPM (Min-Star-Max) Core temperature
17 Boiler temperature
18 Injection interval (reheat) Drain temperature
19 Save all
20 Restore all Door calibration
21 Restart time Boiler water level
22 Screen saver
23 Language
24 Soft ware update
27 Detergent pump
28 Rinse pump
29 CombiWash valve
34 Water pressure
37 Motor RPM 1
38 Motor RPM 2
40 Restart
44 Error log
45 Error statistig
46 Temp CPU
47 Temp I/O
50 Gas control

REVISION 04/19, SW: 3.51 SERVICE MANUAL 21

Setup menu

SETUP MENU
To enter the user menu, press HOT AIR and STEAM for 5 seconds while you are in the
manual mode.
The display briefly shows ”SETUP MENU”. The core temperature display shows ”b” and
the number of the value to be set (see below). You leave the user menu by turning the
turn knob beyond ”0”.

Value Function Description

U1 Oven type Setting up the CPU to the right type of oven.

Confirm the chosen type by pressing the bell.

U2 Oven size Setting up the CPU to the right size of oven.

U3 CombiWash Is the oven fitted with or without combiwash.

0 = without CombiWash.
1 = with CombiWash

U4 Temperature 0 = Celcius
C/F 1 = Fahrenheit

U5 Gas Setting up the power.

0 = Electric
1 = Gas LPG (G30/G31)
2 = Gas G20
3 = Gas G25

U7 Preheat 300°C Setup the oven to preheat at 300°C

U8 Water level set Setup the water level set point for the steam
point generator.
Default value = 75.

U9 Restart after Setup the amount of time the oven can be without
power cut power and continue when the power returns.
(always follow local regulations)

U11 Core probe 0 = Core probe inactive.

1 = Core probe active.

22 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Setup menu

Value Function Description

U12 Drain cooling 0 = Drain cooling deactivated.

1 = Drain cooling on in all water using functions.
2 = Drain cooling active at all time.

U13 Timer start Activate or deactivate timer start.

U14 Demo mode Deactivates the I/O board.

The display will look like the oven is working.
This function is for shows and exhibitions.

U15 Initialise Reset the setting to default setting.

U16 Gas RPM Switch between Minimum, Start and Maximum RPM by
1 = Min rpm pressing the step button.
2 = Start rpm Use the gas settings matrix to set up the three RPM
3 = Max rpm values.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 23

User menu

USER MENU
To enter the user menu, press BELL for 5 seconds while you are in the manual mode.
The display briefly shows USER MENU. The core temperature display shows ”b” and the
number of the value to be set (see below).
You leave the user menu by turning the turn knob beyond ”0”.

Value Function Description

b1 Save defaults Time and temperature can be changed in HOT AIR,

COMBI STEAMING and STEAMING and saved by
pressing ALARM. The alarm control lamp flashes when
data are ready to be saved.
The desired changes should be made before entering
the USER MENU.

b2 Timer start Press STEP to change the various settings of the

timer.
1) DATE. The date flashes in the temperature display.
To set the date, turn the knob. 0 means daily start.
2) HOUR. Set the hour.
3) MINUTE. Set the minute.
4) MODE. Choose a mode by pressing one of the four
mode keys.
5) TEMPERATURE. Set the oven temperature.
6) TIME (duration of program) 0:00-4:00.
Press ALARM to activate the timer. ON appears in
the temperature display and control lamp is on.
Deactivate by pressing ALARM. The oven can now
be turned off with the main switch or it can be left on
standby. The oven starts automatically but only in
manual mode.

b3 Sound low Press STEP and adjust the volume of the alarm during
operation from 0 to 9.

b4 Sound high Press STEP and adjust the volume of the alarm at the
end of a program/mode from 1 to 9.

b5 Sound Press STEP and adjust from 1 to 9.

frequency

b6 Interior light Press STEP: 0 = Continuously on / 5 = Off after 5 min. /

1 (B model) = Continuously on but off when the door is
open / 6 = Off after 5 min. but off while door open.

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 User menu

Value Function Description

b7 Current 0 = desired temperature / 1 = current temperature.

temperature Adjust by pressing STEP.

b8 Extraction Applicable only if the oven has a condensing

extraction hood. 0 = Extraction hood running indepen-
dently of oven / 1 = Extraction hood stops 10 minutes
after oven has stopped.

b9 Time graphics Shown in text display during operation. Change by

pressing STEP.
0 = Display shows mode chosen.
1 = Display alternately shows mode chosen and time
remaining.

b10 Minutes Minutes are shown in temperature display. Change by

pressing temperature key and turning knob. Store by
pressing temperature key again.

b11 Hour Hour is shown in temperature display. See page 11.

b12 Day Day of the month, 1-31. Day of the week, 1 – 7, in time
display. See 11.
In Europe, you can choose to have the computer
switch to summer time automatically. 0 = No change, 1
= Change from/to summer time.

b13 Month Month. See 10.

b14 Year The year 2007 is indicated by ”7”. See 11.

b18 Injection Setting of humidity pulsing. Press temperature key

interval reheat and turn knob to change setting. The value indicates
the number of seconds between each injection into
the oven chamber. If the value is increased, less
humidity is added to the oven chamber. If the value is
reduced, more humidity is added, the factory setting is
every 8 seconds.

b19 Save all Save all parameter settings and programs from the
CPU in the memory of the I/O board.

b20 Retrieve all Retrieve all parameter settings and programs from the
memory of I/O board

b21 Restart time Sets the amount of minutes the restart button will
continue the last step the previous cooking program.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 25

User menu

Value Function Description

b22 Screen saver Interval of seconds before screen saver becomes

active. 0 = 0 sec. / 1 = 10 sec. / 2 = 30 sec. / 3 = 60
sec./ 4 = 180 sec. / 5 = 600 sec. Change by pressing
STEP.

b23 Language Change language by pressing STEP (1 – 9)

The A and B column are chosen when updating the
software.

A B

1 Danish English

2 English Croatian

3 Swedish Slovene

4 Finnish Estonian

5 German Hungarian

6 Spanish Russian

7 French Czech

8 Italien Finish

9 Dutch Polish

b24 SW update Updating of software. Special memory key required.

Contact your local distributor.
In this function, you update the computer software by
means of a special memory key (not a USB key).
1. Insert the memory key.
2. Press the alarm key to view the software version
and language variants.
3. Press the step key to select the language variant.
4. Press the alarm key again to start updating the
process.
The software version of the oven in question is also
shown in the start-up sequence when the oven is
switched on.

26 SERVICE MANUAL REVISION 04/19, SW: 3.51

 TEST Menu

TEST MENU
To enter the user menu, press HOT AIR AND COMBI STEAM for 5 seconds while you are
in the manual mode.
The display briefly shows ”TEST MENU”. The core temperature display shows ”D” and
the number of the value to be set (see below).
You leave the user menu by turning the turn knob beyond ”0”.
SAFETY: Never leave an oven in test mode. Safety functions are disabled, the unit will
not stop heating until safety is triggered.
GAS TEST: Always open the door completely and run the main fan at full speed (1400
RPM) when running a gas unit in test mode.

Value Function Description

d0 Main contactor This function activates contactor K1.

You activate or deactivate the function by pressing
the step key. The function can, however, only be
activated when the fan is on.
To pulse, press the alarm key.
0= OFF, 1= ON.
Status for the main alarms appear in the display as
follows:
Digit 1 fan
Digit 2 oven
Digit 3 generator
Digit 4 Solid State Relay
If ER28 appears, the IO board or wiring harness is
defective.

d1 Heating This function will start heating by activating the SSR.

This function can only be activated when D0 main
contactor and D3 main fan motor is active.

d2 Generator This will heat up the water in the steam generator.

heating This function can only be activated when D0 main
contactor is active and the water level in the steam
generator is high.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 27

TEST Menu

Value Function Description

d3 Fan right This function will start up the main fan motor/motors
at maximum speed 1400 RPM in right-rotation
direction. The main fan motor speed can be changed
by pressing the clock and turning the dial until the
display shows the desired RPM.
This function can only be activated when the D0 main
contactor is active.

d4 Fan Left This function will start up the main fan motor/motors
at maximum speed 1400RPM in Left rotational
direction. The main fan motor speed can be changed
by pressing the clock and turn the dial until the display
shows the desired RPM.
This function can only be activated when D0 main
contactor is active.

d7 Filling valve This function activates solenoid valve MV2.

You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key. 0 = OFF, 1 = ON.

d8 Drain pump This function activates motor M2.

You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key. 0= OFF, 1= ON.

d9 Drain cooling This function activates solenoid valve MV3.

You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key. 0 = OFF, 1 = ON.

d10 Damper motor This function activates motor M3.

In the display next to ”Time”, it is possible to read the
status of the damper motor switch.
OFF= damper open, ON= damper closed.
You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key. 0 = OFF, 1 = ON.

28 SERVICE MANUAL REVISION 04/19, SW: 3.51

 TEST Menu

Value Function Description

d11 Exhaust This function activates the outlet for controlling the
external ventilation, terminals 4 and 5.
In the display next to ”Time”, it is possible to read
which outlet is active.
OFOF = both outlets are off, ONOF = outlet 4 is active
and outlet 5 is off.
OFON = outlet 4 is off and outlet 5 is active. ONON =
both outlets are active.
You activate or deactivate the function by pressing
the step key.
0 = OFOF, 1 = OFON, 2 = ONOF, 3 = ONON.

d12 Cooling fan This function activates motors M7 and M7A.

You activate or deactivate the function by pressing
the step key.

d13 Test sound This function will activate the alarm sound. Press Step
for high sound, and Alarm bell for low sound.

d14 Interior light This function activates H1.

You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key.
0 = OFF, 1 = ON.

d15 Oven tempe- Here it is possible to read the current oven tempe-
rature rature, PT100 sensor P1.
In the field next to ”Temperature”, the current tempe-
rature is shown. If ERR appears, the
sensor circuit is defective.
In the field next to ”Time”, an adjustment value
between 80 and 120 (default 100) is shown.
To adjust the temperature, press the time key until the
digit in the display flashes. Then adjust
upwards or downwards until the correct temperature
is shown. Finally, press the time key
again to save the setting.
The temperature can be adjusted by +/- 10°C.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 29

TEST Menu

Value Function Description

d16 Core probe This function is not available on B models.

temperature C and K models can use only one core temperature
probe.
Here it is possible to read the current temperature of
the core temperature sensor, P2 + P2A.
In the field next to ”Temperature”, the current tempe-
rature is shown. If ERR appears, the
sensor circuit is defective.
In the field next to ”Time”, an adjustment value
between 80 and 120 (default 100) is shown.
To adjust the temperature, press the time key until the
digit in the display flashes. Then adjust
upwards or downwards until the correct temperature
is shown. Finally, press the time key
again to save the setting.
The temperature can be adjusted by +/- 10°C.
You change between the various measuring points of
the core temperature probe by pressing
the step key.
1 = Core temp.probe 1, point 1, 2 = Core temp.probe,
point 2, 3 = Core temp.probe 1, point 3.
4 = Core temp.probe 2, point 1, 5 = Core temp.probe,
point 2, 6 = Core temp.probe 2, point 3.

d17 Steam Here it is possible to read the current steam generator

generator temperature, P3.
temperature In the field next to ”Temperature”, the current temper-
ature is shown. If ERR appears, the
sensor circuit is defective.
In the field next to ”Time”, an adjustment value
between 80 and 120 (default 100) is shown.
To adjust the temperature, press the time key until the
digit in the display flashes. Then adjust
upwards or downwards until the correct temperature
is shown. Finally, press the time key
again to save the setting.
The temperature can be adjusted by +/- 10°C.

30 SERVICE MANUAL REVISION 04/19, SW: 3.51

 TEST Menu

Value Function Description

d18 Drain tempe- Here it is possible to read the current steam generator
rature temperature, P4.
In the field next to ”Temperature”, the current temper-
ature is shown. If ERR appears, the
sensor circuit is defective.
In the field next to ”Time”, an adjustment value
between 80 and 120 (default 100) is shown.
To adjust the temperature, press the time key until the
digit in the display flashes. Then adjust
upwards or downwards until the correct temperature
is shown. Finally, press the time key
again to save the setting.
The temperature can be adjusted by +/- 10°C
(approximately 0.5°C per step).

d20 Door sensor Here it is possible to read the status of and calibrate
door sensor 1 = SE1 and 2 = SE1A.
You change between door sensor 1 and 2 by pressing
the step key.
After some time, the text “DOOR SENSOR” changes to
show the status of the sensor:
>CLOSED<, >OPEN<, >SENS ERROR<. You start the
calibration by pressing the exhaust key.
How to calibrate:
1. Press the damper key.
2. >CLOSE< flashes.
3. Close the door.
4. Press the damper key.
5. >OPEN< flashes.
6. Open door in the first step.
7. Press the damper key.
8. >CALIB OK< or >CALIB ERR< appears.
9. Press the damper key to confirm.
In the display next to the temperature key, it is
possible to read the current value (0 – 120).
In the display next to the time key, it is possible to read
the set point.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 31

TEST Menu

Value Function Description

d21 Water level Here it is possible to read the status of SE2.

In the display next to ”Time”, the conductivity is shown
and it is indicated whether the water
level is high or low
XX|LO = low water level, XX|HI = high water level.
XX = conductivity of the water.
Default setting is approximately 80 with no water and
40.60 with water. The better the conductivity,
the lower the measured value.

d27 Detergent Only possible if the CombiWash function is active

pump This function activates pump M5.
You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key.
0 = OFF, 1 = ON.

d28 Rinse pump. Only possible if the CombiWash function is active

This function activates pump M6.
You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key

d29 CombiWash Only possible with CombiWash function is active.

water This function activates solenoid valve MV4.
You activate or deactivate the function by pressing
the step key.
To pulse, press the alarm key.
0 = OFF, 1 = ON.

d34 Water pressure Here it is possible to read the status of P7.

sensor OF|HI= water pressure adequate, ON|LO= water
pressure inadequate.

d37 Motor RPM 1 Here it is possible to read the number of revolutions

for fan motor 1.
The number of revolutions is shown in the display next
to the temperature key X10.

d38 Motor RPM 2 Here it is possible to read the number of revolutions

for fan motor 2.
The number of revolutions is shown in the display next
to the temperature key X10.

d40

32 SERVICE MANUAL REVISION 04/19, SW: 3.51

 TEST Menu

Value Function Description

d44 Error log. Here it is possible to read which error codes have been
reported. After two seconds, the error log
will show you which error code was reported most
recently and when.
By turning the switch to the right, you will see older
errors. The oven can save 30 errors after
which it deletes the oldest one.
LEAVE THE FUNCTION BY TURNING SWITCH TO THE
LEFT.

d45 Error statistics Here it is possible to read how many times each error
code has occurred. After two seconds, the
oven will show you when the error statistic was last
reset and the total number of errors. By
turning the switch to the right, you can scroll through
all error codes and see how many times
they have occurred.
LEAVE THE FUNCTION BY TURNING SWITCH TO THE
LEFT.

d46 Temperature Here it is possible to read the temperature of the CPU

on CPU board board.
In the display next to ”Temperature”, the temperature
of the CPU board is shown. Maximum 60°C.

d47 Temperature Here it is possible to read the temperatures of the IO

on I/O board board.
In the display next to ”Temperature”, the temperature
of the IO board is shown. Maximum 60°C.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 33

TEST Menu

Value Function Description

d50/d51 Gas burner 1-2

The oven can be operated entirely in the manual mode and in the test function
only. ONLY OPERATE GAS OVENS ON GAS TEST IF YOU HAVE A BASIC KNOWLEDGE
ABOUT THE GAS SYSTEM:
1) Enter test function by pressing the Hot Air key and combi key simultaneously for 2
seconds. The display shows “d 0” and “MAIN CONT”.
2) Press the step key to activate the main contactor so that “1” appears in display.
3) Activate “d 3” or “d 4”, “FAN RIGHT” or “FAN LEFT”. Start the oven chamber fan by
pressing step key until “1” appears in step display. If required, set the fan speed by
pressing the time key and changing the speed with the turn switch (0-100%).
The pre-mix burner should not run at high performance unless the oven chamber fan
is on.
4) Now select “d50” “GAS BURN 1”.
Use the step button to switch between burner 1 and 2.
The gas-air control unit can be started and set and the automatic gas burner control
turned on and off. Also, this is where you can see if the pressure switch and gas valve
are turned on.
Start the automatic gas burner control by pressing the step key.
The step display shows if the control is on (0/1).
Start the gas-air control unit by pressing the fan key.
But first, set the desired speed in time display.
The number shown in the time display can be set between 0 and 9000 at intervals of
100 RPM and is the directly desired RPM speed of the unit.
To change the speed, turn the switch while the number flashes.
The oven controller takes care that the gas-air control unit runs at the desired
speed.
The speed of the gas-air control unit is shown in the temperature display, divided by
10, i.e. a reading of 234 means 2340 RPM.
The LED next to exhaust key indicates when the pressure switch is on.
The LED next to the alarm key indicates when gas valve is on.

Note: The pressure switch and gas valve status is only readable when the automatic
gas burner control is on.

To start the pre-mix burner in test mode, do as follows:

1) Check that fan has stopped.
2) Turn the automatic burner control on by pressing the step key.
3) Allow four seconds for control to detect that the pressure switch is not on.
4) Press the fan key to start the gas-air control unit.
5) The LED next to the exhaust key indicates when the pressure switch is on.
6) Wait 15 seconds until the automatic burner control turns on the gas valve.
The LED next to alarm key indicates when this happens.

34 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Cleaning

CLEANING
Daily cleaning of the oven is recommended for hygienic reasons and to avoid interrup-
tions of operation.
The design of the HOUNÖ ovens allows quick and easy cleaning. The oven chamber is
made of all-welded stainless steel, which makes it splash proof. You will therefore find
the easy-to-use handshower, which is located under the front panel, very suitable for
interior cleaning.
The door sealing is easy to remove, which ensures quick and efficient cleaning under and
around it.
Furthermore, the flat front panel makes exterior cleaning simple and efficient.
To give the oven an extra shine, we recommend HOUNÖ Steel Care Steel Oil, which is
available at www.hounoshop.com.

Cleaning the oven chamber

Use CombiWash and choose between level 1-4.
Note: CombiWash cannot be retrofitted; it can only be installed as an optional extra
when the oven is produced. Therefore CombiWash should be ordered together with the
oven.
You can also use the semi-automatic cleaning program (See Description of Functions
on page 20), or do as follows:
• Always clean in a cold oven or cool the oven chamber down to below 80°C.
• Let the oven run in CombiSmart at 80°C for 15 minutes.
• Apply HOUNÖ PROTECT oven detergent to the sides of the oven chamber, racks,
etc. (according to need), using a soft brush or a spray pistol. Protect your face
and hands as the detergent may cause irritation should it come into contact
with your skin.
• Let the detergent work for 10 minutes. Let the oven run in CombiSmart at 80°C
for 15 minutes.
• Rinse the oven chamber with water (using a soft brush or the handshower
(optional extra).
• If the oven is not connected to a soft-water plant, we recommend that you use
HOUNÖ PROTECT Rinse Aid and wipe the oven chamber with a dry cloth.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 35

Cleaning

Cleaning the Oven Exterior

1. Use a soft, damp cloth and a liquid detergent to clean the oven cabinet on the
outside,
2. Remove the door sealing to clean under and around the door.
3. Treat the surface with HOUNÖ Steel Care Steel Oil to protect it. The steel oil is
available at www.hounoshop.com.
Note: Do not use a water hose or high-pressure cleaner to clean the oven exterior since
it may damage parts of the oven including electronic components.

Cleaning Behind the Filter Housing

You have to remove the filter housing to be able to clean around the fan and the heating
elements.
1. Loosen screws (A) and (B).
2. Turn the filter housing and clean behind it. You dismount the filter housing by lifting it
upwards until it is clear of the pin at the bottom and then tipping it.

36 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Cleaning

Cleaning the Jet Heads

You have to clean the jet heads regularly, when you have used CombiSmart and
ClimaOptima. This must also be cleaned regularly. The Visual Cooking oven comes with
two sets of jet heads. While you clean one set, you can replace them with the other.
1. Unlock the screws to dismount the jet heads.
2. Soak the jet heads in descaling solution overnight.
• The jet head for steam (ClimaOptima and CombiSmart) has the notch facing
downwards (long tube).
• The jet head for CombiWash is located to the right or above the other jet
head. It has the notch facing upwards (short tube).

Jet head
for steam

Jet head for

CombiWash

Cleaning the Filter

The filter is located below the control compartment in front of the spray hose.
You have to unscrew and clean the filter under the front panel on a weekly basis. You
can clean the filter manually or in a dishwasher.
Important: If the filter is not cleaned, the computer may overheat and the oven will fail.
You must remount the filter after it has been cleaned.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 37

Water layout

WATER LAYOUT

38 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Water layout

Component description
Item Description
1 Detergent and rinse pump
2 Water pressure switch
3 Solenoid valve
4 Restriction
5 Solenoid valve
6 Handshower
7 Drain cooling nozzle
8 O-ring seal
9 Washing nozzle for oven size 1.16-1.20-2.20
10 Washing nozzle for oven size 1.16-1.20-2.20
11 Washing nozzle for oven size 1.06-1.08-1.10-1.12-2.06-2.10-2.14
12 Washing rotor in the top of the oven cavity
13 Rubber hose connection the stem generator and the cavity
14 Steam generator
15 Water level sensor
16 Ø50 stainless steel drain tube
17 Heating element for steam generator
18 Steam generator drain pump
19 Ø50mm stainless steel tube
20 Rubber hose connection between number 19 with number16
21 Drain temperature sensor
22 Drip tray front door
23 O-ring seal
24 Ø50mm tube with connection to the drip tray
25 Drip tray back door, PassThrough versions

REVISION 04/19, SW: 3.51 SERVICE MANUAL 39

I/O board led

I/O BOARD LED

Description, connection of the different led on the I/O to help under stand the different
functions of the I/O board

No Colour Volt Plug. Pin DESCRIPTION

7 Green Main Voltage to main contator OK.
8 Green ER5 J14 Pin 5 Voltage fan alarm switch OK.
9 Green ER4 J14 Pin 4 Voltage oven overheating switch OK.
10 Green ER3 J14 Pin 3 Voltage from steam generator switch OK.
11 Green Er12 J14 Pin 2 Voltage from SSR overheating switch

12 Yellow 24V F2 J10 Fuse F2 Power supply to I/O board.

13 Yellow 24V F1 J2 Pin Fuse F1 is OK.
1,3,5
14 Yellow 24V F3 J8 Pin 3,6 Fuse F3 is OK.

15 Red Reset The I/O board is in a reset mode (flashes only at

start).
16 Green 12V The internal 12V is present.
17 Green 5V The internal 5V is present.
18 Green 3,3V The internal 3,3V is present.
19 Green 5V out J1 Pin 13 External 5V for door sensor and RPM sensor.
20 Green 12V J1 Pin 15 External 12V for the ClimaOptima sensor
21 Green 24V J18 pin 1 External 24V voltage for the gas fan interface.
J19 Pin 1 This option is only present on I/O board
J20 Pin 1 P/N 30900015

22 Green Com Slow flashing when I/O communicates with the CPU
23 Green Com Fast flashing when data received from CPU
RX
24 Green Com TX Fast flashing when data is send to the CPU

25 Red Test 1 Lights when communication is not working

26 Red Test 2 Lights shortly under start

40 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Frequency inverter

FREQUENCY
INVERTER
Always check that the frequency inverter potentiometers and dip
switches are set up correct, when replacing the frequency inverter.
To gain access to the potentiometer for adjustment. open the small
tranparent hatch with a small screwdriver. as shown in the drawing.

ADJUSTMENT OF THE THREE POTENTIOMETERS OF THE FREQUENCY INVERTER

Motor i nom This potentiometer controls the current output of the frequency
inverter.
This potentiometer must be set to 100%

ACC/DEC This potentiometer controls is the acceleration and deceleration of

the main fan motor in seconds.
The potentionmeter must be set a few degrees past 5.
It is very impotent that the acceleration of the fan is 10 sec. +/-1 sec.
USE THE TEST MENU FAN
If the acceleration is too fast the inverter might be switching off due
to overload. Too slow will result in error 14.
HI FREQ This potentiometer controls the Hz output of the frequency inverter.
This potentiometer must be set to NOM.

SETTINGS OF THE DIP SWITCHES ON THE FREQUENCY INVERTER

HZ Set to 50HZ
SILENT Set to ON
LOAD Set to P&F
JOG Hz Set to 5
RELAY Set to FLT
Al offset Set to Off
Autoreset Set to Off
Hi freq Set to Off

REVISION 04/19, SW: 3.51 SERVICE MANUAL 41

Error Codes

ERROR CODES
ERROR CODE DESCRIPTION

3 Generator too hot.

4 Oven too hot.
5 Fan too hot.
6 Drain too hot.
7 Oven sensor defective.
8 Core probe not connected.
9 Generator sensor defect.
10 Drain sensor defective.
11 Water shortage.
12 SSR to hot.
13 Generator too hot.
14a Fan to slow.
14b Fan to slow.
16 I/O board to hot.
18 Data error
19 Internal error.
20 No communication.
22 Program terminated.
23 Oven too hot.
24 Empty error.
25 Probe error
28 Error in alarm.
29 Door sensor error.
34 Water pressure too low.
40 I/O board too hot.

42 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Error Codes

ERROR CODE DESCRIPTION

43 Wrong software
44 Exhaust error.
45 Error with 24V.
50 Press switch active.
51 Press switch off.
52 Gas valve failure.
53 Gas fan no rpm.
54 Gas fan speed error.
55 Ignition error.
56 Gas error.
57 Gas stop.
60 Press switch active 2.
61 Press switch active 2.
62 Gas valve failure 2.
63 Gas fan no rpm 2.
64 Gas fan speed error 2.
65 Ignition error 2.
66 Gas error 2.
67 Gas stop 2.
Errors 50-57 lower burner, errors 60-67 upper burner

REVISION 04/19, SW: 3.51 SERVICE MANUAL 43

Troubleshooting ERROR CODES

TROUBLESHOOTING
ERROR CODES
Troubleshooting procedure step by step on error codes.
If the oven displays an error code, try the solutions below before contacting HOUNÖ
technical service at techsupport@houno.com.
After each step is carried out, be sure to test if the oven is working again.

Error Code 3

The generator thermo switch has tripped because the temperature has risen above
135°C/275°F. Press the Q2 button under the oven to reconnect.

Steps Checklist Solution

1 Go to the test menu (main alarm) to see

if the thermo switch has tripped. Reset
the switch.

2 Test if the solenoid valve, level sensor, If not, ensure that there is
empty pump, and the solid state relay no dirt in the solenoid valve.
are working properly.

3 Check the cable and the cable plugs

4 - Change the overheating

sensor.

5 - Change the I/O board.

44 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 4

The overheating switch of the oven chamber is off because the oven chamber
temperature has risen above 350°C/662°F. Press the Q1 button at the bottom of
the oven to reset the switch. If the oven comes with two fan motors, there are 2
overheating switches.

Steps Checklist Solution

1 Go to the test menu (main alarm) to see

if the overheating thermo switch has
tripped. Reset the switch.

2 Test whether the fan is running and

whether the solid state relay is working
properly.

3 Check the cable and the cable plugs.

4 - Change the overheating

sensor.

5 - Change the I/O board.

Error Code 5

The fan motor is too hot (above 120°C/248°F). Let the motor cool off for about
20-30 minutes and then try turning it on again.

Steps Checklist Solution

1 Go to the test menu (main alarm) to see

which information is displayed.

2 Check the cable and the cable plugs.

3 Check the motor temperature sensor Change the fan motor.

4 Check the fan motor windings. Change the fan motor.

5 - Change the I/O board.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 45

Troubleshooting ERROR CODES

Error Code 6

The drain temperature has been above 75°C/167°F for more than five minutes. It is
normally kept below 60°C/140°F.

Steps Checklist Solution

1 Check that the water is turned on.

2 Check that the water supply connected

to the oven is cold and not hot.

3 Check that the solenoid valves is If not, change the solenoid

functional. valve.

4 Check whether the temperature sensor If broken, change the sensor.

is broken. Measure the real temperature
and compare it to the temperature
measured by the test function.

5 Clean the jet and the solenoid valve at

the drain, and then check the temper-
ature again.

Error Code 7

The temperature sensor in the oven chamber is broken. The oven cannot be used
until the error has been corrected.

Steps Checklist Solution

1 Go to the test menu (oven) to see which

temperature is displayed.

2 Check the cable and the cable plugs and

change the plug if necessary.

3 Test the sensor using an ohmmeter, If not, change the sensor.

and check whether the value matches
the value in the table and the current
temperature.

4 - Change the I/O board.

46 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 8

The probe is broken or is not connected properly. The program cannot be used until
the error has been corrected.

Steps Checklist Solution

1 Go to the test menu (miscellaneous) to

see which information is displayed.

2 Check the cable and the cable plugs and

change the plug, if necessary.

3 Test the sensor using an ohmmeter, If not, change the sensor.

and check whether the value matches
the value in the table and the current
temperature.

4 - Change the I/O board.

Error Code 9

The temperature sensor in the boiler/steam generator is not working properly.

Programs using steam cannot be used until the error has been corrected.

Steps Checklist Solution

1 Go to the test menu (steam generator)

to see which information is displayed.

2 Check the cable and the cable plugs and

change the plug, if necessary.

3 Test the sensor using an ohmmeter, If not, change the sensor.

and check whether the value matches
the value in the table and the current
temperature.

4 - Change the I//O board.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 47

Troubleshooting ERROR CODES

Error Code 10

The temperature sensor in the drain is broken. The oven can still be used, but the
error has to be corrected as soon as possible.

Steps Checklist Solution

1 Go to the test menu (oven) to see which

temperature is displayed.

2 Check the cable and the cable plugs and

change the plug, if necessary.

3 Test the sensor using an ohmmeter, If not, change the sensor.

and check whether the value matches
the value in the table and the current
temperature.

4 - Change the I/O board.

Error Code 11

There is not enough water. The steam generator was not filled to high level water
within the maximum time.

Steps Checklist Solution

1 Go to the test menu (steam generator)

to see if the water level is correct. Adjust
the water level, if necessary. Check that
water is turned on. The water pressure
should be at least 2 bars.

2 Test whether the solenoid valve and Clean the solenoid valve.
the level sensor are working (is 24VAC
measured at the coil when the fill valve is
activated?)

3 - Change the I/O board.

48 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 12

The heat sink for the solid state relay is too hot because the temperature has risen
above 120°C/248°F. Let it cool off for 20-30 minutes and then retry.

Steps Checklist Solution

1 Go to the test menu (Main Alarm) to see

which information is displayed.

2 Check the cable and the cable plugs, and

then tighten the solid state relay.

3 - Clean the intake filter.

4 - Change the overheating

sensor.

5 - Change the I/O board.

Error Code 13

The temperature of the top heating element of the steam generator has risen above
130°C/266°F.

Steps Checklist Solution

1 Go to the test menu (steam generator) The steam generator may

to see which information the computer have to be descaled.
displays.

2 Check the cable and the cable plugs. Change the plug, if
necessary.

3 Test the sensor using an ohmmeter, and If not, change the sensor.
check whether the value matches the
value in the table.

4 - Change the I/O board.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 49

 Troubleshooting ERROR CODES

Error Code 14A + 14B

1) The rotational speed of the fan is too slow. (a=lower fan B=upper fan)

Steps Checklist Solution

1 Verify that the intake filter is not blocked. Clean, if necessary.

2 Go to the test menu and test if the fan

motor is running.

3 Check that the fan wheel is not blocked.

4 Check that the main contactor can be If 24VAC is measured, but

activated. the main contactor is not
4) Activate the main contactor in the activated, change the main
fan test menu. Verify that there is contactor.
24VAC between A1 and A2 on the main
contactor.

5 Verify that the frequency inverter Check the contactor.

receives 230VAC on L/R and N/S.
5)
6 Is the red LED in the frequency inverter Change the frequency
flashing? inverter.
Find out how often and check the Contact HOUNÖ service at
meaning of the flashes. techsupport@houno.com.
6)
7 Verify that the rotation sensor measures If you can measure 5VDC,
5VDC. (Measure 5VDC between the but there is no signal from
black and the red cable on the rotation the sensor, change the
sensor.) sensor.

8 Verify that the 5VDC diode on the IO

board lights up.
8)
9 Disconnect the J1 plug. If the 5VDC diode
emits light, there is a short circuit in the
wiring.

10 Does the diode light up? If not, change the IO board.

50 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 16

The I/O board temperature has risen above 60°C/140°F.

Steps Checklist Solution

1 Go to the test menu to see which infor-

mation the computer displays.

2 Check whether the ambient temperature Move the oven if necessary,

is too high. and clean the intake filter.

3 Check whether the test function temper- Move the oven or the heat
ature matches the current temperature. source.

5 - Change the I/O board.

Error Code 18

Data error

Steps Checklist Solution

1 - Go to setup and set the

oven setup.

2 - Replace the CPU.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 51

Troubleshooting ERROR CODES

Error Code 19

An internal error occurred. The oven server process is not responding. Oven server
process failed.

Steps Checklist Solution

1 - Restart the oven.

2 - Update the software.

3 Change the computer.

Error Code 20

An internal error occurred. A communication failure occurred between the computer

and the IO board. The IO board software is not responding. Wrong software version
on the CPU.

Steps Checklist Solution

1 Check the wire connection between the Change the IO board or the
I/O board and the CPU board. CPU board, if necessary.

52 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 22

Program interrupted. There was a power outage while the program was running. The
power outage lasted for so long that the program cannot be restarted.

Steps Checklist Solution

1 - The oven can be set up

to restart after a power
outage. Contact the service
personnel.

Error Code 23

The oven is too hot for CombiWash to start.

Steps Checklist Solution

1 Cool down the oven and restart

CombiWash

2 Go to the test menu to see which infor-

mation the computer displays.

3 Check that the temperature in the oven Cool down the oven and
chamber matches the temperature that restart CombiWash.
is displayed.

4 Test the temperature sensor using an Change the sensor.

ohmmeter, and check whether the value
matches the value in the table.

5 - Change the I/O board.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 53

Troubleshooting ERROR CODES

Error Code 24

Empty error. The steam generator could not be emptied during flushing. The level
sensor reports high water level when the generator is emptied. The drain may be
blocked.

Steps Checklist Solution

1 Go to the test menu and activate the If pump is running, find the
empty pump of the steam generator. block in the drain tubes.

2 If pump is not running, measure that the

pump receives 230V/120 V.

3 The pump is receiving 230V and the Check that there is no scale
pump is trying to rotate but it is stuck or foreign objects blocking
the empty pump. Remove
the scale or foreign object
from the empty pump.

4 Use the test menu to check if the signal Clean and descale the level
from the water level sensor reads the sensor, and test it using
empty and full signal. the test menu, and then
check if the generator can
be emptied now. Replace
the sensor if it does not
work during test and it is
descaled.

5 - Change the I/O board.

Error Code 25

Probe error. Temperature probe is defective.

Steps Checklist Solution

1 Check connections

2 - Change core probe.

54 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error Code 28

An invalid combination of the mains alarm has been detected. The mains alarm is
not displayed correctly.

Steps Checklist Solution

1 Go to the test menu (alarm test) to

see which one of the overheat safety
switches is not sending a feedback signal
to the I/O board connector J14.

2 Check the switch and cable and the cable Change the plug and repair
plugs from that specific overheating the wire, if necessary, and
sensor and the wire to J14. then test if the alarm has
disappeared.

3 If the error persist, and the feedback Replace the I/O board.
signal to the I/O board is ok.

Error Code 29

The door sensor is not working properly. Note: the oven does not stop working when
the door is opened. The oven can be used.

Steps Checklist Solution

1 Go to the test menu to see which infor-

mation the computer displays.

2 Check the cable and the cable plugs, and

the test if the sensor is working.

3 Check the magnet on the drip slide. Change the drip slide.

4 - If the magnet works, change

the door sensor, and
remember to calibrate the
door afterwards.

WARNING
The oven does not stop working when the door is opened.
The oven can still be used with caution.

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Troubleshooting ERROR CODES

Error Code 34

The water pressure is too low. (less than 1.5 bar).

Steps Checklist Solution

1 Pull one of the wires from the water If YES, replace the sensor.
pressure switch to check if the signal
changes to YES.

1 Check that the water is turned on. Clean the solenoid valve
filter.

2 Check that the water pressure is at least

2.5 bars.

Error Code 40

The I/O board temperature has been too high. Note that this is a warning. If the
temperature continues to rise, the oven will stop and display error code 16.

Steps Checklist Solution

1 Clean the filter at the bottom of the Clean the filter at the
panel and check that the cooling fan bottom of the panel.
behind the front panel is running.

2 Check that the cooling fan behind the Replace the cooling fan, if
front panel is running. necessary.

3 Replace the I/O board.

Error Code 43

Wrong software.

Steps Checklist Solution

1 Contact HOUNO Technical Support at Please upload the correct

techsupport@houno.com. software.

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 Troubleshooting ERROR CODES

Error Code 44

Exhaust error. At every startup the CPU makes the valve run a reference round.

Steps Checklist Solution

1 Use the technicians test menu, oven test.

Test if the exhaust valve works and the
switch sends a signal back to the CPU.

2 If the motor is rotating the valve but If exhaust signal changes in

there is no on/off signal from the switch, the test menu, replace the
bridge the two wires on the exhaust complete exhaust valve.
motor switch.

3 If the motor is not running, check that 24V is present, replace the
there is a 24V power supply for motor. motor.

4 If there is no 24V power supply for the Repair the damaged wire.
motor, measure the wires from the I/O
board to the connector for the valve
motor.

5 Measure the 24V power supply directly If the 24V is present, replace
on the I/O board. the I/O board.

6 Measure the 24V power supply from the If the 24V is not present,
transformer. replace the transformer.

Error Code 45

There is no 24VAC. The main contactor output is not working.

Steps Checklist Solution

1 Check fuse F1. Replace fuse F1.

2 Measure the 24V on I/O board connector If not, repair the wires.
J1 wire pin no 1-3-5).

2 Check the led F1 24V on the I/O board.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 57

Troubleshooting ERROR CODES

Gas Error Codes

Error codes from number 50 to 67 are gas oven specific.
50-57 bottom burner.
60-67 upper burner.

Error 50/60

Pressure switch error. The pressure switch is active at start (timeout 20 sec.)

Steps Checklist Solution

1 Go to the test menu, and adjust the Change the pressure switch.
pressure switch. Verify that the pressure
switch is working properly.

Error 51/61

Pressure switch error. The pressure switch is not active when the gas fan is running.

Steps Checklist Solution

1 Go to test function.
Check that the relay K16 is working
properly.

2 Adjust the pressure switch. Change the pressure switch.

Verify that the pressure switch is working
properly.

58 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Troubleshooting ERROR CODES

Error 52/62

Gas valve failure. The gas valve does not open after five startup attempts
(timeout 20 seconds).

Steps Checklist Solution

1 Go to the test menu. Perform the startup

sequence.

2 Check that the controller receives If there is no feedback,

feedback from the pressure switch and perform the startup
the gas valve. sequence again.

3 Check that the relays are working Change the relays.

properly.

4 Check the Dungs control box.

Error 53/63

Fan RPM. The pressure switch is active at start (timeout 20 seconds).

REVISION 04/19, SW: 3.51 SERVICE MANUAL 59

Troubleshooting ERROR CODES

Error 54/64

Fan error. The gas fan RPM before ignition is not correct.

Steps Checklist Solution

1 Go to the test menu. Test the gas fan. If not, test the gas fan. Verify
Verify that the RPMs are registered. that there is power input.

2 Test the gas fan: Set the speed at 2000 Remove the low voltage
RPM and verify that the actual RPM plugs from the IO board J18,
reaches 2000 RPM. J19 and J20. The fan should
run at full speed. If no RPMs
are registered, change the
gas fan.

3 Verify that the main contactor is Ensure that the main

activated. contactor is activated, and
then go to the test menu
and test the fan again.

4 Check the fuses and the wires.

Error 55/65

Ignition failure. Warning only: did not ignite at first try.

Steps Checklist Solution

1 Check, clean, or change the electrode or

burner.

2 Go to test menu.
Perform the startup sequence.

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 Troubleshooting ERROR CODES

Error 56/66

Gas failure. No flame has been detected after five attempts.

Steps Checklist Solution

1 Check if the gas supply is available.

2 Check, clean, or change the electrode or

burner.

3 Go to the test function.

Perform the startup sequence.

Error 57/67

Stop during operation. Warning only: gas stop during operation.

Steps Checklist Solution

1 Check, clean, or change the electrode or

burner.

2 Go to the test function.

Perform the startup sequence.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 61

GAS Burner Electrode Adjustments

GAS BURNER
ELECTRODE
ADJUSTMENTS
Oven size 1.06
13kW

8 mm

4 mm

52 mm

62 SERVICE MANUAL REVISION 04/19, SW: 3.51

 GAS Burner Electrode Adjustments

Oven size 1.10, 1.20, 2.10, 2.20

21 kW, 24kW

8 mm

4 mm

56 mm

REVISION 04/19, SW: 3.51 SERVICE MANUAL 63

Gas Pressure

GAS PRESSURE

1. Prepare the gas-pressure meter.

2. Open the gas-test nipple using a flat-headed screwdriver.
3. Turn the screw counter-clockwise.

When the gas-test nipple is opened, gas will escape. Be prepared and
have the gas-pressure meter ready before opening the test nipple.

Measure the static gas pressure.

1. Switch on the unit and measure the dynamic gas pressure. The dynamic gas
pressure must be between the following values
• “1.8-2.5 kPa” - “18-25 mbar” for natural gas.
• “3-5.7 kPa” – “30-57 mbar” for LPG.

Note: Local regulations might state otherwise. Please comply with local rules and
regulations.
1. Close the gas-test nipple using a flat-headed screwdriver.
2. Turn the screw clockwise.

Check all gas lines for gas leakages using an appropriate leakage
tester.

64 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Gas Burner Settings

GAS BURNER SETTINGS

When you adjust the gas burner, the tolerances are as follows:
Maximum rpm setting: +/-0.2%.
Minimum rpm setting: +/-0.2%.

Adjustment “CE” gas ovens (burner 1)

Houno Gas Oven Adjustment Settings Hot Air Burner 1 “Bottom”

O2%, CO2% O2%, CO2% RPM Adjustment Air Proving

“MAX” RPM “MIN”, RPM normal operation Switch - ON
Heat Ovn Gas inlet “u16” “u16” “u16”
Type of gas power O2% CO2% RPM kW O2% CO2% RPM OFF -> ON
types pressure Min Start Max
kW

13 kW 1.06/5 18-25 mbar 4.1% 9.4% 6700 13 kW 4.6% 9.1% 4800 4800 4800 6700 3100 +/-100
21 kW 1.10/8 18-25 mbar 4.3% 9.3% 6300 21 kW 4.1% 9.4% 2700 2700 3900 6300 2300 +/-100
Nature gas 42 kW 1.20/15 18-25 mbar 4.3% 9.3% 6300 21 kW 4.1% 9.4% 2700 2700 3900 6300 2300 +/-100
(G20) 21 kW 2.06 18-25 mbar 4.1% 9.4% 6200 21 kW 4.1% 9.4% 3800 3800 3900 6200 2800 +/-100
24 kW 2.10 18-25 mbar 4.1% 9.4% 6600 24 kW 4.5% 9.2% 2800 2800 3600 6600 2300 +/-100
48 kW 2.20 18-25 mbar 4.1% 9.4% 6600 24 kW 4.5% 9.2% 2800 2800 3600 6600 2300 +/-100

13 kW 1.06/5 18-25 mbar 4.0% 9.3% 6800 13 kW 4.3% 9.1% 4800 4800 4800 6800 3100 +/-100
21 kW 1.10/8 18-25 mbar 4.0% 9.3% 6400 21 kW 4.0% 9.3% 2800 2800 3900 6400 2300 +/-100
Nature gas 42 kW 1.20/15 18-25 mbar 4.0% 9.3% 6400 21 kW 4.0% 9.3% 2800 2800 3900 6400 2300 +/-100
(G25) 21 kW 2.06 18-25 mbar 3.8% 9.4% 6200 21 kW 3.8% 9.4% 3800 3800 3900 6200 2800 +/-100
24 kW 2.10 18-25 mbar 3.8% 9.4% 6600 24 kW 4.1% 9.2% 2800 2800 3600 6600 2300 +/-100
48 kW 2.20 18-25 mbar 3.8% 9.4% 6600 24 kW 4.1% 9.2% 2800 2800 3600 6600 2300 +/-100

13 kW 1.06/5 28-57 mbar 4.5% 11.0% 6500 13 kW 5.1% 10.6% 4800 4800 4800 6500 3100 +/-100
21 kW 1.10/8 28-57 mbar 4.5% 11.0% 6000 21 kW 4.5% 11.0% 2600 2600 4300 6000 2300 +/-100
LPG 3BP 42 kW 1.20/15 28-57 mbar 4.5% 11.0% 6000 21 kW 4.5% 11.0% 2600 2600 4300 6000 2300 +/-100
(G30/G31) 21 kW 2.06 28-57 mbar 4.5% 11.0% 6200 21 kW 4.5% 11.0% 3800 3800 3900 6200 2800 +/-100
24 kW 2.10 28-57 mbar 4.0% 11.4% 6200 24 kW 4.7% 10.9% 2800 2800 3600 6200 2300 +/-100
48 kW 2.20 28-57 mbar 4.0% 11.4% 6200 24 kW 4.7% 10.9% 2800 2800 3600 6200 2300 +/-100

13 kW 1.06/5 30-50 mbar 5.2% 10.3% 6800 13 kW 5.2% 10.3% 4800 4800 4800 6800 3100 +/-100
21 kW 1.10/8 30-50 mbar 5.4% 10.2% 6300 21 kW 5.4% 10.2% 3900 3000 3900 6300 2300 +/-100
LPG 3P 42 kW 1.20/15 30-50 mbar 5.4% 10.2% 6300 21 kW 5.4% 10.2% 3900 3000 3900 6300 2300 +/-100
(G31) 21 kW 2.06 30-50 mbar 5.4% 10.2% 6400 21 kW 5.4% 10.2% 3800 3800 3900 6400 2800 +/-100
24 kW 2.10 30-50 mbar 5.1% 10.4% 6600 24 kW 5.8% 9.9% 2900 2900 3600 6600 2300 +/-100
48 kW 2.20 30-50 mbar 5.1% 10.4% 6600 24 kW 5.8% 9.9% 2900 2900 3600 6600 2300 +/-100

REVISION 04/19, SW: 3.51 SERVICE MANUAL 65

 Gas Burner Settings

Adjustment “ETL” gas ovens (burner 1)

Houno Gas Oven Adjustment Settings Hot Air Burner 1 “Bottom”
O2%, CO2% O2%, CO2% RPM Adjustment Air Proving
“MAX” RPM “MIN”, RPM normal operation Switch - ON
Heat Ovn Gas inlet “u16” “u16” “u16”
Type of Gas Power O2% CO2% RPM BTU/hr O2% CO2% RPM OFF -> ON
Types Pressure Min Start Max
BTU/hr

58000 1.06/5 3.2-8.0 in H2O 4.1% 9.4% 6700 58000 4.6% 9.1% 4800 4800 4800 6700 3100 +/-100
87000 1.10/8 3.2-8.0 in H2O 4.3% 9.3% 6300 87000 4.1% 9.4% 2700 2700 3900 6300 2300 +/-100
NAT 174000 1.20/15 3.2-8.0 in H2O 4.3% 9.3% 6300 87000 4.1% 9.4% 2700 2700 3900 6300 2300 +/-100
(G20) 81800 2.06 3.2-8.0 in H2O 4.1% 9.4% 6200 81800 4.1% 9.4% 3800 3800 3900 6200 2800 +/-100
95500 2.10 3.2-8.0 in H2O 4.1% 9.4% 6600 95500 4.5% 9.2% 2800 2800 3600 6600 2300 +/-100
190000 2.20 3.2-8.0 in H2O 4.1% 9.4% 6600 95500 4.5% 9.2% 2800 2800 3600 6600 2300 +/-100

60000 1.06/5 5.2-14 in H2O 5.2% 10.3% 6800 60000 5.2% 10.3% 4800 4800 4800 6800 3100 +/-100
87000 1.10/8 5.2-14 in H2O 5.4% 10.2% 6300 87000 5.4% 10.2% 3900 3000 3900 6300 2300 +/-100
LP 174000 1.20/15 5.2-14 in H2O 5.4% 10.2% 6300 87000 5.4% 10.2% 3900 3000 3900 6300 2300 +/-100
(G31) 81800 2.06 5.2-14 in H2O 5.4% 10.2% 6400 81800 5.4% 10.2% 3800 3800 3900 6400 2800 +/-100
95500 2.10 5.2-14 in H2O 5.1% 10.4% 6600 95500 5.8% 9.9% 2900 2900 3600 6600 2300 +/-100
190000 2.20 5.2-14 in H2O 5.1% 10.4% 6600 95500 5.8% 9.9% 2900 2900 3600 6600 2300 +/-100

Adjustment “CE” gas ovens (burner 2)

Houno Gas Oven Adjustment Settings Hot Air Burner 2 “Top”
O2%, CO2% O2%, CO2% RPM Adjustment Air Proving
“MAX” RPM “MIN”, RPM normal operation Switch - ON
Heat Ovn Gas inlet “u17” “u17” “u17”
Type of Gas Power O2% CO2% RPM kW O2% CO2% RPM OFF -> ON
Types Pressure Min Start Max
kW

13 kW 1.06/5 18-25 mbar

21 kW 1.10/8 18-25 mbar
Nature Gas 42 kW 1.20/15 18-25 mbar 4,3% 9,3% 6300 21 kW 4,1% 9,4% 2700 2700 3900 6300 2300 +/-100
(G20) 21 kW 2.06 18-25 mbar
24 kW 2.10 18-25 mbar
48 kW 2.20 18-25 mbar 4,1% 9,4% 6600 24 kW 4,5% 9,2% 2800 2800 3600 6600 2300 +/-100

13 kW 1.06/5 18-25 mbar

21 kW 1.10/8 18-25 mbar
Nature Gas 42 kW 1.20/15 18-25 mbar 4,00% 9,3% 6400 21 kW 4,00% 9,3% 3900 2800 3900 6400 2300 +/-100
(G25) 21 kW 2.06 18-25 mbar
24 kW 2.10 18-25 mbar
48 kW 2.20 18-25 mbar 3,80% 9,40% 6600 24 kW 4,10% 9,20% 2800 2800 3600 6600 2300 +/-100

13 kW 1.06/5 28-57 mbar

21 kW 1.10/8 28-57 mbar
LPG 3BP 42 kW 1.20/15 28-57 mbar 4,5% 11,0% 6000 21 kW 4,5% 11,0% 2600 2600 4300 6000 2300 +/-100
(G30/G31) 21 kW 2.06 28-57 mbar
24 kW 2.10 28-57 mbar
48 kW 2.20 28-57 mbar 4,0% 11,4% 6200 24 kW 4,7% 10,9% 2800 2800 3600 6200 2300 +/-100

13 kW 1.06/5 30-50 mbar

21 kW 1.10/8 30-50 mbar
LPG 3P 42 kW 1.20/15 30-50 mbar 5,4% 10,2% 6300 21 kW 5,4% 10,2% 3900 3000 3900 6300 2300 +/-100
(G31) 21 kW 2.06 30-50 mbar
24 kW 2.10 30-50 mbar
48 kW 2.20 30-50 mbar 5,1% 10,4% 6600 24 kW 5,8% 9,9% 2900 2900 3600 6600 2300 +/-100

66 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Gas Burner Settings

Adjustment “ETL” gas ovens (burner 2)

Houno Gas Oven Adjustment Settings Hot Air Burner 2 “Top”
O2%, CO2% O2%, CO2% RPM Adjustment Air Proving
“MAX” RPM “MIN”, RPM normal operation Switch - ON
Heat Ovn Gas inlet “u17” “u17” “u17”
Type of Gas Power O2% CO2% RPM BTU/hr O2% CO2% RPM OFF -> ON
Types Pressure Min Start Max
BTU/hr

58000 1.06/5 3.2-8.0 in H2O

87000 1.10/8 3.2-8.0 in H2O
NAT 174000 1.20/15 3.2-8.0 in H2O 4.3% 9.3% 6300 87000 4.1% 9.4% 2700 2700 3900 6300 2300 +/-100
(G20) 81800 2.06 3.2-8.0 in H2O
95500 2.10 3.2-8.0 in H2O
190000 2.20 3.2-8.0 in H2O 4.1% 9.4% 6600 95500 4.5% 9.2% 2800 2800 3600 6600 2300 +/-100

60000 1.06/5 5.2-14 in H2O

87000 1.10/8 5.2-14 in H2O
LP 174000 1.20/15 5.2-14 in H2O 5.4% 10.2% 6300 87000 5.4% 10.2% 3900 3000 3900 6300 2300 +/-100
(G31) 81800 2.06 5.2-14 in H2O
95500 2.10 5.2-14 in H2O
190000 2.20 5.2-14 in H2O 5.1% 10.4% 6600 95500 5.8% 9.9% 2900 2900 3600 6600 2300 +/-100

REVISION 04/19, SW: 3.51 SERVICE MANUAL 67

Changing type of gas

Changing type of gas

Converting A Gas Oven to Another Gas
Type
When you convert to another gas type, never adjust the offset governor “Minimum”.
1. Make the following adjustment on the “Max rpm” screw
• From G20 --> G25, one turn counter-clockwise.
• From G20 --> LGP, two turns clockwise
• From G25 --> G20, one turn clockwise.
• From G25 --> LGP, three turns clockwise.
• From LPG --> G20, two turns counter-clockwise.
• From LPG --> G25, three turns counter-clockwise.
2. Set up the controller for the new gas type.
3. Verify or change if necessary the preset rpm in the controller.
4. Perform flue gas analysis or adjustments. For more information, see the installation
manual.

68 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Switch adjustment

Switch adjustment

If the gas to the oven is not turned off before the pressure switch is
adjusted, the oven may ignite during the adjusting process creating
high CO values. This can cause fatal poisoning.

1. Turn off the gas inlet.

2. Enter the Test menu D.
3. D0 activate the main contactor.
4. D1 fan af max speed and open the door.
5. On the Test menu, scroll to Test D50.
6. Press the clock button, and rotate the dial to select the RPM needed for the
specific model.
7. Adjust the pressure switch to continue at the set rpm RPM.
8. The actual RPM value must match the values in the following table. If the value
does not match, you must adjust the pressure switch.

REVISION 04/19, SW: 3.51 SERVICE MANUAL 69

Gas Sequence Diagram

GAS SEQUENCE
DIAGRAM
Pressure-switch table OFF->ON

Oven types RPM Tolerance

1.06 3100 +/-100

1.10 2300 +/-100

1.20 2300 +/-100

2.06 2800 +/-100

2.10 2300 +/-100

2.20 2300 +/-100

1. If the registered value is lower than the value in the table, you have to adjust the
pressure switch clockwise. ½ turn adjusts approximately 150 RPM.
2. If the registered value is higher than the value in the table, you have to adjust
the pressure switch counterclockwise. ½ turn adjusts approximately 150 RPM.
3. When you have completed the adjustment, turn the controller OFF and ON.
4. Turn on the gas inlet.

70 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Gas Components

GAS COMPONENTS

Gas components position 1.06, 1.10, 2.10, 2.20

Interface relay

Coil gas-air unit

Burner
electrode

Ignition trafo

Gas-air unit

Dungs
Pressure switch control box

REVISION 04/19, SW: 3.51 SERVICE MANUAL 71

 Gas Components

Pressure switch

Interface relay

Coil gas-air unit

Burner
electrode

Ignition trafo

Gas-air unit
Dungs control
box
Interface relay

Coil gas-air unit

Burner
electrode

Ignition trafo

Gas-air unit

Pressure switch

72 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Gas Components

Gas Components

Gas-Air unit Coil gas-air unit Cable coil

kW Black 9kW White 18kW Red 27kW

Voltage 230VAC 120VAC 230VAC 120VAC 230VAC 120VAC 230VAC 120VAC 230VAC 120VAC

Part no. 32700180 32700177 32700181 32700178 32700182 32700179 32700170 32700173 32700169 32700174

1.06 x x x

1.10 x x x

1.20 x x x
120VAC

2.06

2.14/2.10 x x x

2.20 x x x

1.06 x x x

1.10 x x x

1.20 x x x
230VAC

2.06

2.14/2.10 x x x

2.20 x x x

Burner w. electrode Electrode Ignition trafo Cable ignition trafo Dungs control box

kW 9kW 18/27kW 9kW 18/27kW

Voltage 230VAC 120VAC 230VAC 120VAC 230VAC 120VAC

Part no. 32720022 32720021 32700126 32700055 32700166 32700172 32800073 32800073 32700165 32700171

1.06 x x x x x

1.10 x x x x x

1.20 x x x x x
120VAC

2.06

2.14/2.10 x x x x x

2.20 x x x x x

1.06 x x x x x

1.10 x x x x x

1.20 x x x x x
230VAC

2.06

2.14/2.10 x x x x x

2.20 x x x x x

REVISION 04/19, SW: 3.51 SERVICE MANUAL 73

Identifying parts

IDENTIFYING PARTS

13 kW - Black

21-24 kW – Red

Yellow: 120VAC - Coil

Red: 230VAC – Coil

74 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Error codes on Dungs’ Control Box

ERROR CODES ON
DUNGS’ CONTROL BOX

REVISION 04/19, SW: 3.51 SERVICE MANUAL 75

Error codes on Dungs’ Control Box

76 SERVICE MANUAL REVISION 04/19, SW: 3.51

 Error codes on Dungs’ Control Box

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Error codes on Dungs’ Control Box

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 Side 1 af 1

PT 100 table

PT 100 TABLE

http://img.docstoccdn.com/thumb/orig/79579313.png 09-07-2013

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SERVICE AND REPAIR

SERVICE AND REPAIR

• All maintenance and repair must be carried out by qualified installation and
service personnel only. Installation or service by other than qualified personnel
may result in damage to the oven and/or injury to the operator.
• When cleaning the oven, only use cleaning detergent that matches the speci-
fications from the factory. Do not use corrosive cleaners not intended for oven
cleaning your Visual Cooking oven.

SAFETY
Please read the safety instructions carefully.
• Ensure that installation is carried out by qualified installation and service
personnel only.
• Read, understand, and follow the instructions for use.
• Place trays filled with hot liquid at the bottom runners of the oven chamber and
practice extreme caution when removing the tray from the oven chamber.
• Do not store petrol or other flammable vapors or liquids in the vicinity of this
appliance.
• Do not touch hot surfaces. The temperature of some surfaces may exceed
60°C/140°F or more.
• Do not attempt to operate or open the oven during the automatic cleaning
process.
• Use the parking brakes on the trolley wheels to prevent trolleys from rolling on
uneven floors.
• Contact qualified service personnel before you make changes to the set-up of
the oven. Incorrect changes may have serious effects on its reliability in service.

WARRANTY
To see the complete list of warranty terms, please go to our webpage:
http://www.houno.com/support/technical-support/4-year-warranty.
aspx

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 warranty

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 HOUNÖ A/S
ALSVEJ 1
DK-8940 RANDERS SV
DENMARK

T: +45 8711 4711

E: houno@houno.com

www.houno.com
www.hounoshop.com

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