Bosch Condens 8300i W Installation And Maintenance Instructions Manual page 52

Troubleshooting
Fault text on the display, description
1037 W Outside temp. sensor faulty - heating back-
up operation active
1065 W System pressure sensor faulty or not
connected
1068 W Outside temp. sensor or lambda probe
faulty.
1075 W Heat exchanger temp sensor short circuit
1076 W Heat exchanger temp sensor disconnected 1. Connect the plug to the temperature sensor correctly.
2085 V Internal fault
2908 V System fault boiler electronics / basic
controller
2910 V Fault in flue system
2914 - V Boiler electr. system fault
2916
2920 V Fault in flame monitoring
2923- V Boiler electr. system fault
2926
2927 B Flame extinguished during burner operation 1. Open the main shut-off valve.
2928 V Internal fault
52
Remedy
1. If an outside temperature sensor is not desired. Select the room temperature-
dependent configuration in the control device.
2. If there is no continuity, rectify the fault.
3. Clean corroded terminals in the outside sensor housing.
4. If values do not match, replace the sensor.
5. If the sensor values matched, but the voltage values do not match, replace the control
unit.
1. Connect the plug to the pressure sensor correctly.
2. Check pressure sensor connecting lead, replace if necessary.
3. Check the pressure sensor, replace if necessary.
1. Connect the plug to the temperature sensor correctly.
2. Connect the plug to the control device correctly.
3. Attach the temperature sensor correctly.
4. Check the temperature sensor, replace if necessary.
5. Check temperature sensor connecting lead, replace if necessary.
1. Connect the plug to the temperature sensor correctly.
2. Check the temperature sensor, replace if necessary.
3. Check temperature sensor connecting lead, replace if necessary.
2. Check the temperature sensor, replace if necessary.
3. Check temperature sensor connecting lead, replace if necessary.
1. Unlock.
2. Disconnect power from the system for 30 seconds.
3. Replace the burner control unit.
If the fault persists following a reset, the burner control unit is faulty and must be replaced.
1. Install the flue system.
2. Remove any deposits from the flue system.
If the fault persists following a reset, the control device is faulty and must be replaced.
Check control device, replace if necessary.
1. Check air/gas ratio control valve cabling.
2. Check air/gas ratio control valve.
If the fault persists following a reset, the control device or the air/gas ratio control valve is
faulty and must be replaced.
2. Open the device shut-off valve.
3. Interrupt the power supply of the appliance and check the gas line.
4. Carry out function check for ignition.
5. Carry out function check for ionisation.
6. Connect the plug for the ionisation and ignition sections correctly.
7. Establish protective conductor connection (PE) in the control device.
8. Check flame sense electrode, replace if necessary.
9. Check ignition electrode, replace if necessary.
10.Check ignition electrode connecting lead, replace if necessary.
11.Replace the connecting lead to the flame sense electrode.
12.Set the burner correctly/replace the burner nozzles.
13.Set the burner at minimum rated load.
14.Check air/gas ratio control valve, replace if necessary.
15.Check the flue system, repair if required.
16.The interconnected room air supply is too small or the size of the ventilation opening
is too small.
17.Clean the heating block on the flue gas side.
18.Check control device/burner control unit, replace if necessary.
1. Perform reset.
2. Replace control device/burner control unit.
Condens 8300i W – 6721841531 (2022/10)