Troubleshooting
43
Condens 7000 WP – 6721842519 (2022/03)
2927 B
No flame detected after ignition
1. Open the main shut-off valve.
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 and repair if necessary.
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.
2928 V
Internal fault
1. Perform reset.
2. Replace control device/burner control unit.
2931 V
System fault boiler electronics / basic
controller
1. Perform reset.
2. Replace control device/burner control unit.
2940 V
System fault burner control unit
1. Perform reset.
2. Replace control device/burner control unit.
2946 V
Incorrect code plug detected
Replace boiler identification module/coding plug (Bosch contact customer service).
2948 B
No flame signal with low output
Burner starts automatically after purging.
If this fault occurs frequently, check CO
2
setting.
2949 B
No flame signal with high output
The burner is automatically restarted following purging.
1. Check burner gaskets, replace if required.
2. Reduce output.
2950 B
No flame signal following starting procedure Burner starts automatically after purging.
Set gas/air ratio correctly.
2951 V
Loss of flame too many times
1. Open the main shut-off valve.
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 ionisation.
5. Connect the plug for the ionisation and ignition sections correctly.
6. Establish protective conductor connection (PE) in the control device.
7. Check flame sense electrode, replace if necessary.
8. Check ignition electrode, replace if necessary.
9. Check ignition electrode connecting lead, replace if necessary.
10.Check flame sense electrode connecting lead, replace if necessary.
11.Set the burner correctly/replace the burner nozzles.
12.Set the burner at minimum rated load.
13.Check air/gas ratio control valve, replace if necessary.
14.Check the flue system and repair if necessary.
15.The interconnected room air supply is too small or the size of the ventilation opening
is too small.
16.Clean the heating block on the flue gas side.
17.Check control device/burner control unit, replace if necessary.
2952 V
Internal fault when testing the ionisation
signal
1. Perform reset.
2. Replace control device/burner control unit.
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ry Fault text on the display, description
Remedy
