Although Appliance Switches Off, Flame Still Detected - Worcester ZSBR 7-28 ICS1 Service Booklet

F 7
and

Although appliance switches off, flame still detected

Check
1. Electrode(s) dirty or defective.
B Power OFF the appliance.
2.
B Disconnect the boiler electrical
connection.
B Remove PCB control board.
PCB control board damp?
3. Is there a problem with the flue?
B Check CO
level in combustion
2
air.
> 0,2 % CO
2
4. The PCB control board is damaged.
7 181 465 347 (01.07)
flashing.
yes:
no:
yes:
no:
?
Action
B Power OFF the appliance.
B Replace electrode assembly.
B Turn ON the appliance.
B Press , does appliance restart???
F7? ↓2.
B Dry PCB control board (e.g. with hair dryer).
B Refit PCB control board.
B Reconnect the boiler electrical connection.
B Press
, does appliance restart???
F7? ↓3.
↓3.
B Check flue and repair or replace if necessary.
↓4.
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change PCB control board.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
Rectifying faults
33