After Appliance Switches Off Flame Is Detected - Worcester ZSBR 7-28 ICS1 Service Booklet

Rectifying faults
FA
and

After appliance switches off flame is detected

Check
1. Is condensation trap in condensing
boiler blocked?
2. Electrodes faulty.
3. Problem with flue?
B Check CO
level in combustion
2
air.
> 0,2 % CO
2
4. The gas valve is damaged.
5. Check if the 20-pin connector lead
assembly is damaged.
6. The PCB control board is damaged.
34
flashing.
yes:
no:
yes:
?
no:
Action
B Clean condensation trap discharge pipe.
B Press
, does appliance restart???
FA? ↓2.
↓2.
B Replace electrode assembly.
B Turn ON the appliance.
B Press
, does appliance restart???
FA?
B Power OFF the appliance.
↓3.
B Check flue and repair or replace if necessary.
B Press
, does appliance restart???
FA?
B Power OFF the appliance.
↓4.
↓4.
B Change the gas valve.
B Turn ON the appliance.
B Press
, does appliance restart???
FA?
B Power OFF the appliance.
↓5.
B Change the 20-pin connector lead assembly.
B Turn ON the appliance.
B Press
, does appliance restart???
FA?
B Power OFF the appliance.
↓6.
B Disconnect the boiler electrical connection.
B Change PCB control board.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
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