Bosch Condens 2000 W User manual

6 720 644 062-00.1O
Condens 2000 W
Service Manual
ZWB24 - 1AR...
TT-RH/PRMM21 - 01.2017

2| Content
Content
1 Safety precautions and symbols 3
1.1 Safety precautions 3
1.2 Symbols 3
2 Service Function Adjustment 4
2.1 Service Function 4
2.2 Overview Service Function 4
2.2.1 1. Service Level 4
2.2.2 2. Service Level 5
3 Failures / Errors 6
3.1 Elimination of errrors 6
3.2 Failure / Error Codes Overview 7
3.3 Failure codes and corrections steps 8
3.4 Sensor (NTC) Values 24
3.4.1 Flow Temperature Sensor 24
3.4.2 Domestic Hot Water Temperature Sensor 24
3.4.3 Flue Gas Safety Temperature Sensor ( Behind
Burner) 24
3.5 Electrical Datas 25
3.6 Electrical Circuit Diagram 26
3.7 Structure 27
3.8 Function Diagram 29
4 Gas Values (CH and DHW) 30

Safety precautions and symbols | 3
1 Safety precautions and symbols
1.1 Safety precautions
If you smell gas
BTurn off gas service cook.
BOpen windows.
BDo not operate any electrical switches.
BExtinguish any naked flames.
BLeave the building and telephone the gas company and
authorized dealer from an outside phone.
If you smell fumes from the appliance
BSwitch off the appliance.
BOpen windows and doors.
BInform your heating engineer.
Fitting and Modifications
BFitting of the appliance or many modifications to be appli-
ance may only be carried out by a compotent perEND.
BFlue systens must not be modified in any way.
BIf the appliance has a type B.. flue system : Ventilation
openings in doors, windows and walls must not be sealed
or restricted. If draught-proof windows are installed, meas-
ures must be taken to ensure there is an adequate supply
of air to the appliance for combustion.
Inspection / Maintenance
BWe recommend take out a to have the system regulary
serviced in order to ensure that it functions reliably and
safely.
BOnly use original spare parts.
Combustible materials
BDo not store or use any combustible materials (paper, thin-
ners, paints etc.) in the vicinty of the appliance.
Combustion Air / Ambient Air
BKeep combustion air/ambient air free of corrosive sub-
stances (e. g. halogenated hydrocarbons which contain
chlorine or fluorine compounds). In this way corrosion can
be prevented.
Instructions to the customer
BExplain to the customer how the appliance works and how
to operate it.
BAdvise the customer that he / she must not make any mod-
ifications to the appliance or carry out any repairs on it.
1.2 Symbols
Signal words indicate the seriousness of the hazard in terms
of the consequences of not following the safety instructions.
•Caution indicates that minor damage to property could
result.
•Warning indicates that minor personal injury or serious
damage to property could result.
•Danger indicates that serious personal injury could result.
In particularly serious cases, lives could be at risk.
Notes contain important information in cases where there is
no risk of personal injury or damage to property.
Safety instructions in this document are identi-
fied by a warning-triangle symbol and are print-
ed on a grey background.
Notes are identified by the symbol shown on
the left. They are bordered by horizontal lines
above and below the text.

4| Service Function Adjustment
2 Service Function Adjustment
2.1 Service Function
Service functions are in divided in 2 level :
•1. Level (see page 4)
•2. Level (see page 5)
Fig. 1
1Stand by (On/off) Button
2„Up (+)“ Button
3„Down (-)“ Button
4Temparature Display (°C)
5Service Button
2.2 Overview Service Function
2.2.1 1. Service Level
Operation
Change or query of a service function :
BPress buttonfor5second.Theservicefunctionwillbe
shown on Display (e.g. 1.2.C).
BSelect the desired/requested service code with “+” or “-”
button.
BPress button again (for entering).
After that you will see the selected (default) value on Dis-
play.
Changing / Adjustment of Value:
BChange the values with “+” or “-” button.
Storage/Save of Value :
BPress button until [ ]symbol will be shown on Display.
Exit from Service Level :
BFor the exit from service level press the or Stand by
button.
The flow temperature will be shown again on display.
1. Level
1
0
2
3
4
bar
45
2
3
1
6 720 644 501-07.1O
Service Code Description Range Initial (Factory
setting)
1.2.C Automatical Air Purging (0 = offý, 1= active ) Total time : 2 min.
and 20 sec on/off intervall 0 - 1 0
1.2.F Operating Mode : (0 = Normal, 3= min. output, 4 = max. output) 0, 3 , 4 0
1.3.b Burner Anticycling 1 - 10 min. 3 min.
1.3.C Burner start hysterisis (for flow temp. NTC) 0 - 10 K 5 K
1.5.b Fan overrun 1 - 18 (x10) sec. 3 (=30 sec.)
1.6.A Last failure on memory 00 - FF -
1.6.d Display actual water flow rate by turbine ( l/min. ) 0 - 99
1.7.A Operating LED (1 = on, 0 = 30 off after 30 sec.) 0 - 1 1
Tab. 1 1. level service functions

Service Function Adjustment | 5
2.2.2 2. Service Level
Operating
Change or query of a service function :
BTo enter to 2. service level must be entered first in 1. level.
Press button for 5 second. The service function onf1.
level will be shown on Display (e.g. 1.2.C).
BTo enter to 2. level : Press both “+” and “-” buttons for 3
second. The service function of 2. level will be shown on
Display (e.g. 2.1.A).
BSelect the desired/requested service code with “+” or “-”
button.
BPress button again (for entering)..
After that you will see the selected (default) value on Dis-
play.
Changing / Adjustment of Value:
BChange the values with “+” or “-” button.
Storage/Save of Value :
BPress button until [ ]symbol will be shown on Display.
Exit from Service level :
BFor the exit from service level press the or Stand by
button.
The flow temperature will be shown again on display.
2. Level
Service
Code Description Range Initial (Factory Setting)
2.1.A CH max. heat output 30 - 100 % 100 %
2.1.b DHW max. heat output (in winter mode) 30 - 100 % 100 %
2.2.b CH max flow temperature 35 - 82°C 82°C
2.3.d CH min. heat output 30 - 100 % 30 %
2.3.F Delay time after DHW in winter mode (Heating mode is disabled for this
period of time) 0 - 5 min. 1 min.
2.8.A Software version number e.g.. 162 112 -
2.8.E Reset to factory (default) setting 0 0
2.9.A Operation mode permanent : (0 = Normal, 1= min. power, 2 = max.
power) 0 - 2 0
2.9.E Delay time for the turbine ( each unit = 0,5 sec.) 1 - 6 2
2.9.F Pump over run) (CH circuit) 0 - 10 min. 3
2.A.A Actual flow temperature ºC -
2.A.b Actual DHW temperatur ºC -
2.A.F Actual combustion chamber temperature ºC -
2.b.d Selection of flue length (MAP Value) (0 = off, 1 - 10 : fan speed accord-
ing flue pipe length, see flue manuel for details) 0 - 10 0
2.b.F Solar mode delay time (sec.) 1 - 50 1
2.c.F Pump "over run” (DHW mode) 0 - 30 sec. 5 sec.
2.0.A Gas Convertion (0 = NG, 1 = LPG) 0 -1 0
Tab. 2 2. level service functions

6| Failures / Errors
3 Failures / Errors
3.1 Elimination of errrors All regulation, control and safety equipment of appliance is
controlled by the control unit.
BIf any failure during operation occurs, symbol and
maybe will start to flash also. In additional the failure
code will be shown on display (e.g. EA).
BIf and symbol on display flash:
BForthe reset:Press and Standbybuttonuntil and
symbol expire on display.
The appliance will start up again and the flow temperature
will be displayed.
BIf only symbol flashes:
BSwitch the appliance first off and then on again by means
of the standby key.
The appliance will start up again and the flow temperature
will be displayed.
If a failure can not be eliminated :
BContact your approved installer or Customer Service for
assistance, providing details of the fault and the appliance.
Danger: Explosion !
BTurn off gas cock before working on gas-
bearing components.
BCheck for leaks before working on gasbear-
ing components.
Danger: Poisoning !
BCheck for leaks before working on gasbear-
ing components.
Danger: Risk of electric shock !
BAlways disconnect the power supply to the
appliance at the mains before carrying out
any work on the electrical systems and com-
ponents (fuse, circuit breaker).
Leaking water may damage the Cotronic mod-
ule.
BCover the Cotronic module before working
on any parts that carry water.
For an overview of faults, see page 7.

Failures / Errors | 7
3.2 Failure / Error Codes Overview
Failure Code
on Display Failure Descripton Steps
MAP not selected (Fan speed adjustment accord-
ing the flue pipe length). Check the adjustment /selection via service function 2.b.d).
A2 Combustion chamber NTC failure (behind burner) :
when the temperature by CC NTC reached to limit Check the and the heat exchanger surface, whether is blocked or not. And check the sensor and the connec-
tions.
A6 1)
1) Failure codes is adapted to the EMS (>FD660)
Combustion chamber NTC failure (behind burner) :
when NTC not detected or open circuit Check the and the heat exchanger surface, whether is blocked or not. And check the sensor and the connec-
tions.
A7 Domestic hot water temperature sensor not correct
installed or failure. Check the sensor and cable connection.
B3 --> d5 2)
2) Failure codes is adapted to the EMS (>FD660)
Short circuit / failure in water level switch. Check the condensate water drain and recuperator
(condens-heatexchanger).
CE --> d4 3)
3) Failure codes is adapted to the EMS (>FD660)
Gradient limit : Temperature rises too rapidly in
heating mode. Check the pump, system pressure and by-pass circuit.
C7 Fan sensor not detected. Check the fan.
C8 Fan speed can not reached to target speed. Check the fan for the blockage and the electrical supply.
d7 Modulator coil failure (regulator valve on gas valve) Check the cable connection.
EA Ignition lock-out (flame not detected) (pump is run-
ning). Check the gas cock, gas pressure, electrode and the cable connection.
E2 Flow temperature sensor failure (pump is running). Check the flow temperature sensor and the connection.
E9 Overheat lock-out by temperatur limiters (STBs)
(Flue gas + prim. Heatexchanger). In this case ;
Heat demands is blocked and pump stops 3 min.
later.
Check the system presseure, temperature sensor, pump
and fuses on board. Discharge the air in system. Check
also the flue gas pipe and heatexchanger.
FA Safety valve leaks. Check the gas valve, the cable connection and electrode
set.
Tab. 3 Failure codes

8| Failures / Errors
3.3 Failure codes and corrections steps
A2and operating LED is flashing.
Combustion chamber NTC failure (behind burner) : when the temperature by CC NTC reached to limit 1)
Control Step Action
1. Check if combustion chamber NTC dam-
aged or not and the position.
BSwitch off the appliance.
BPull the NTC cables out.
BMeasure NTC resistance.
Are the values correct ? (see NTC val-
ues)
yes: BCheck the cable connection.
A2 failure still exist ? -->2.
no: BChange the NTC.
BConnect the cable.
BSwitch on the appliance.
A2 failure still exist ? -->2.
2. Check if cable damaged or not.
BSwitch off the appliance.
BIn case of NTC is cahnged :
- Pull the NTC cables out.
- Measure NTC resistance.
- Reconnect the NTC cable.
BPull out the 20 poled connector on
control unit.
BMeasure the NTC resistance directly
on 20 poled connector. Are the meas-
ured values on NTC and cocnector dif-
ferent ?
yes: BChange the cable harness.
BSwitch on the appliance.
A2 failure still exist ? -->3.
no: -->3.
3. Is there any blockage on flue gas pipe? yes: BRemove the blockage.
A2 failure still exist ? -->4.
no: -->4.
4. Is the correct MAP (fan speed) value
according flue gas pipe length choosen ? no: BAdjust correct MAP value according flue gas pipe length and diameter. See capitel 7.2.
A2 failure still exist ? -->5.
yes: -->5.
5. Is fan running correct ? no: BChange the fan.
A2 failure still exist ? -->6.
yes: -->6.

Failures / Errors | 9
6. Check the burner gas pressure. Are the
values OK ? yes: BCorrect the gas pressure values. If not possible, change the gas valve.
A2 failure still exist ? -->7.
no: -->7.
7. Is the heat exchanger and recuperator
surface dirty or damaged (blockage) ? yes: BRemove the blockage.
A2 failure still exist ? -->8.
no: -->8.
8. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.
1) The sensor is activated after 1 minute. After 3. failure the boiler is blocked. By first 2. time it will be reseted automaticly after 15 min.
A2and operating LED is flashing.
Combustion chamber NTC failure (behind burner) : when the temperature by CC NTC reached to limit 1)
Control Step Action

10 | Failures / Errors
A6and operating LED is flashing.
Combustion chamber NTC failure (behind burner) : when NTC not detected or open circuit
Control Step Action
1. Check if combustion chamber NTC dam-
aged or not and the position.
BSwitch off the appliance.
BPull the NTC cables out.
BMeasure NTC resistance.
Are the values correct ? (see NTC val-
ues)
yes: BCheck the cable connection.
A6 failure still exist ? -->2.
no: BChange the NTC.
BConnect the cable.
BSwitch on the appliance.
A6 failure still exist ? -->2.
2. Check if cable damaged or not.
BSwitch off the appliance.
BIn case of NTC is cahnged :
- Pull the NTC cables out.
- Measure NTC resistance.
- Reconnect the NTC cable.
BPull out the 20 poled connector on
control unit.
BMeasure the NTC resistance directly
on 20 poled connector. Are the meas-
ured values on NTC and cocnector dif-
ferent ?
yes: BChange the cable harness.
BSwitch on the appliance.
A6 failure still exist ? -->3.
no: -->3.
3. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

Failures / Errors | 11
A7and operating LED is flashing.
DHW (Domestic Hot Water) NTC not installed correctly or defect.
The appliance doesn’ t run in summer mode. It works in winter mode and shows the failure code with alternately.
Control Step Action
1. Check the DHW NTC whether it is correct
installed or not. A7 failure still exist ? -->2.
2. Check if water NTC damaged or not ?.
BSwitch off the appliance.
BPull out NTC cables.
BMeasure resistance of NTC (Ohm).
Is the NTC resistance value OK ?
yes: BChange the cable harnness.
BSwitch on the appliance.
A7 failure still exist ? -->3.
no: -->4.
3. Check if cable damaged or not.
BIn case of NTC is cahnged :
- Pull the NTC cables out.
- Measure NTC resistance.
- Reconnect the NTC cable.
BSwitch off the appliance.
BPull out the 20 poled connector on con-
trol unit.
BMeasure the NTC resistance directly on
20 poled connector. Are the measured
values on NTC and cocnector different
?
yes: BChange the cable harnness.
BSwitch on the appliance.
A7 failure still exist ? -->4.
no: -->4.
4. Check the DHW circuit in main heat
exchanger whether it is calcified or not. BIn case of calcification, clean it with special pump. If nec- essary change the heat exchanger.
A7 failure still exist ? -->5.
5. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

12 | Failures / Errors
B3 / d5 and operating LED is flashing.
Short circuit / failure in water level switch in recuperator (condens heat exchanger).
Control Step Action
1. Check the siphon line.
Is there any blockage ?
yes: BRemove the blockage.
BSwitch on the appliance.
B3 / d5 failure still exist? -->2
no: -->2.
2. Check the water level switch.
Is the resistance lower 300 kOhm ?
yes: BAccumulated water in recuperaotr or switch contacts
are wet.
BIt can be blockage at recuperator drain. Correct it.
BIs the siphon connection adapter in right position. It
should be in vertical position.
BLeakage in water level switch ?. If yes, change it.
B3 / d5 failure still exist? -->3.
no: BShort circuit in connection cable. If necessary, change
it.
B3 / d5 failure still exist? -->3.
3. Electronic card is defect. BNotice the changed parameters.
BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.
BAdjust again according noticed parameters.

Failures / Errors | 13
CE / d4 and operating LED is flashing.
A fast temperature increase detected in central heating (CH) (> 2,7 K/sec).
The appliances will be resetet automaticly, if the flow temp. < 40 ºC.
Control Step Action
1. BCheck system pressure on manome-
ter.
Is the system pressure > 0,5 bar ?
yes: -->2.
no: BFill the system with water.
CE / d4 failure still exist ? -->2.
2. BIs there air in the system ?. yes: -->3.
no: BRemove the air in system.
CE / d4 failure still exist ? -->3.
3. BCheck if water is circulated ? yes: -->4.
no: BCheck and clean pump, filters and return and flow
valves.
CE / d4 failure still exist ? -->4.
4. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

14 | Failures / Errors
C7 and operating LED is flashing.
Fan sensor not detected.
( This failure only occurs if there is a sensor or the cable physical defect)
Control Step Action
1. Is th fan cables damaged ? yes: BSwitch off the appliance.
BChange the cables.
BSwitch on the appliance.
C7 failure still exist ? -->2.
no: -->2.
2. Is there any problem at fan sensor and
cable ?
BSwitch off the appliance.
BCheck the sensor and cable.
yes: BChange the cable and sensor.
BSwitch on the appliance.
C7 failure still exist ? -->3.
no: -->3.
3. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

Failures / Errors | 15
C8 and operating LED is flashing.
Target fan speed can not reached or blockage problem.
Control Step Action
1. Is the flue gas pipe blocked ? no: -->2.
yes: BSwitch off the appliance.
BClean the flue gas pipe.
BSwitch on the appliance.
C8 failure still exist? -->2.
2. Check the power voltage supply.
Is voltage below 160 V AC ?
yes: BSwitch off the appliance.
BInform related persons/company.
BSwitch on the appliance.
C8 failure still exist? -->3.
no: -->3.
3. Check the fan it self. Is there any block-
age or others problems? no: -->4.
yes : BSwitch off the appliance.
BChange the fan.
BSwitch on the appliance.
C8 failure still exist? -->4.
4. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

16 | Failures / Errors
d7and operating LED is flashing.
Appliance doesn’t modulate / Regulator valve problem (don’t regulate to max. position).
Control Step Action
1. Check if the regulator valve cable dam-
aged or not and the connection. Are the
connections wrong?
yes: BChange the cable harness or correct it.
BSwitch on the appliance.
d7 failure still exist ? -->2.
no: -->2.
2. Check the resistance from regulator valve.
BSwitch off the appliance.
BPull out the 20 poled connector on con-
trol unit.
BMeasure the resistance.
Is deviation of resistance values ?
yes: BChange the cable harness.
BSwitch on the appliance.
d7 failure still exist ? -->3.
no: -->3.
3. Check the resistance from regulator valve.
BVoltage / current on reg. valve ?
BMeasure the resistance directly on gas
valve.
Is there deviation of resistance values
between two messurements ?
yes: BChange the gas valve.
BSwitch on the appliance.
d7 failure still exist ? -->4.
no: -->4.
4. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.

Failures / Errors | 17
E9and operating LED is flashing.
Overheat lock-out by temperatur limiters (2 x STB : Flue gas + prim. Heatexchanger). In this case ; Heat demands is
blocked and pump stops 3 minutes later.
Control Step Action
1. Is the system pressure between 1 - 2
bar? yes: -->2.
no: BFill water in sysytem.
BBleed the system 1).
BPress RESET button and restart again.
E9 failure still exist? -->2.
2. Is the circulation pump blocked ? yes: BEliminate the blockage (turn the shaft).
If not succesful :
BSwitch off the appliance.
BCut mains supply.
BDrain the water from appliance.
BChange the pump.
BFill with water and bleed the system again.
BConnect to main supply.
BSwitch on the appliance.
BPress RESET button and restart again.
E9 failure still exist? -->3.
no: -->3.
3. Check the flue gas pipe line.
Is there any blockage ?
yes: BCheck the flue gas pipe and remove the blockage.
BSwitch on the appliance.
BPress RESET button and restart again.
E9 failure still exist? -->4.
no: -->4.
4. Check the recuperator.
Is there any blockage?
yes: BClean the recuperator. Replace if necessary.
BSwitch on the appliance.
BPress RESET button and restart again.
E9 failure still exist? -->5.
no: -->5.

18 | Failures / Errors
5. BSwitch off the appliance.
BCheck the temperature limiter (STB)
on recuperator.
Ist the circuit open or wrong installed ?
no: -->6.
yes: BChange the temperature limiter (STB) or correct the
installation.
BSwitch on the appliance.
-->6.
6. Electronic card is defect. BSwitch off the appliance.
BCut mains supply.
BChange the electronic card.
BConnect to main supply.
BSwitch on the appliance.
BEND
1) If the air inside not removed/discharged, can be also used the manuel air vent valve in recuparator.
E9and operating LED is flashing.
Overheat lock-out by temperatur limiters (2 x STB : Flue gas + prim. Heatexchanger). In this case ; Heat demands is
blocked and pump stops 3 minutes later.
Control Step Action

Failures / Errors | 19
EAand operating LED is flashing.
Ignition lock-out (flame not detected) (pump is running)
Control Step Action
1. Dose the burner flame can be seen? yes: -->6.
no: -->2.
2. Gas inlet cock open? yes: -->3.
no: BOpen the gas inlet cock.
BPress RESET button and restart again.
EA failure still exist? -->3.
3. Air in the gas pipe line? yes: BOpen the gas inlet cock.
BPress RESET button and restart again.
EA failure still exist? -->4.
no: -->4.
4. Ist the thermal gas inlet cock activated ?
(if it is installed)
yes: BChange the cock.
BPress RESET button and restart again.
EA failure still exist? -->5.
no: -->5.
5. Natural gas :
Is there any gas pressure regulator at the
house entrance ?
yes: BCheck if the montage of the gas pressure regulator
assembly is correct or not ? If necessory correct it.
BMeasure the gas inlet pressure. If there is a deviation
inform the gas distributor company.
BPress RESET button and restart again.
EA failure still exist? -->6.
no: -->6.
LPG (liquid gas):
Is there sufficient gas flow in the LPG line
to operate appliance ?
yes: -->6.
no: BIs the tank full enough ?
BIs there any air in the gas pipe?
BIs the external tank magnet valve tripgered ?
BIs the gas entry pressure OK? ( if too high check the
regulator).
BPress RESET button and restart again.
EA failure still exist?-->6.
6. Is the groun d i n g connection done cor-
rectly? yes: -->7.
no: BCorrect ground connection.
BPress RESET button and restart again.
EA failure still exist ? -->7.

20 | Failures / Errors
7. Is the gas valve working ?
BSwitch off the appliance.
BPull out the gas valve cables.
BMeasure resistances from safety
valves.
yes: BConnect the cables.
BSwitch on the appliance.
BPress RESET button and restart again.
EA failure still exist ? -->8.
no: BCut mains supply.
BClose the gas inlet cock.
BChange the gas valve.
BOpen the gas inlet cock.
BConnect to main supply.
BConnect the cables.
BSwitch on the appliance.
BMake sure there is no gas leakage leaking.
BPress RESET button and restart again.
EA failure still exist ? -->8.
8. Is the ignition correct ? yes: -->12.
no: -->9.
9. Check connection of ignition cable and
electrode is correct or not? yes: -->10.
no: BConnect the cable.
BPress RESET button and restart again.
EA failure still exist ? -->10.
10. Is the ignition cable assembled correctly? yes: -->11.
no: BSwitch off the appliance.
BCorrect the ignition cable connection.
BSwitch on the appliance.
BPress RESET button and restart again.
EA failure still exist ? -->11.
EAand operating LED is flashing.
Ignition lock-out (flame not detected) (pump is running)
Control Step Action