Worcester CDi Combi N.G Service Booklet page 49

F7
and RESET button and fault indicator LED are flashing.
Although appliance switches off, flame still detected
Check
1. Electrode(s) dirty or defective?
B Switch OFF the appliance.
B Remove electrode assembly and
bracket and check for wear,
deposits and mechanical damage.
2. Problem with flue?
B Check CO level in combustion air
2
in the flue
(with outer casing fitted).
Is CO level above 0.2%?
2
3. The PCB is damaged.
Tab. 27 F7 Error codes
8 716 115 748 (2009/09)
Supplied By www.heating spares.co Tel. 0161 620 6677
Action
yes: B Replace electrode assembly.
B Switch ON the appliance.
B Press the reset button for 3 seconds and release it.
After releasing the appliance re-starts.
F7? go to 2
no: B Refit electrode assembly.
B Switch ON the appliance.
B Press the reset button for 3 seconds and release it.
After releasing the appliance re-starts.
F7 go to 2
yes: There are flue gases in the combustion air.
B Check flue and repair or replace if necessary.
F7? go to 3
no: go to 3
B Make a note of the altered service settings.
B Switch OFF the appliance.
B Disconnect the boiler power connection.
B Change PCB control board.
B Reconnect the appliance power connection.
B Switch ON the appliance.
B Restore service settings previously noted down.
RECTIFYING FAULTS
49