Worcester Bosch Fault Code F7

Welcome to the fault-codes section of this site. The following table or page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. You may be guided through the fault finding sequence or steps, for rectifying your boiler with this fault code. Suggested repair solutions may be provided by a link to a repair page. NB Some fault codes are only applicable to a specific range of boilers only.

F7 and fault indicator LED are flashing – Although appliance switches off, flame still detected.

CheckAction
1.Electrode(s) dirty or defective?
- Switch OFF the appliance.
- Remove electrode assembly and bracket and check for wear, deposits and mechanical damage.		yes:- Replace electrode assembly.
- Switch ON the appliance.
- Press the reset button for 3 seconds and release it.
After releasing the appliance re-starts.

F7? go to 2
no:- Refit electrode assembly.
- Switch ON the appliance.
- Press the reset button for 3 seconds and release it.
After releasing the appliance re-starts. F7 go to 2
2.Problem with flue?
- Check CO2 level in combustion air
in the flue
(with outer casing fitted). Is CO2 level above 0.2%?		yes:There are flue gases in the combustion air.
- Check flue and repair or replace if necessary. F7? go to 3
no:go to 3
3.The PCB is damaged.Make a note of the altered service settings. B Switch OFF the appliance.
- Disconnect the boiler power connection.
- Change PCB control board.
- Reconnect the appliance power connection.
- Switch ON the appliance.
- Restore service settings previously noted down.

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