Worcester CDi Combi N.G Service Booklet page 38

RECTIFYING FAULTS
d5
and fault indicator LED are flashing. (Boiler not available for demands)
Condensate float switch in condensate pump defective
Check
1. B Power OFF the appliance.
B Disconnect the boiler mains
connection.
Check if condensate float switch is
connected on PCB via ST19 4-5
2. B Disconnect plug on condensate
pump.
Measure the float switch for
continuity.
Is there continuity?
3. B unplug connector ST19.
Test harness for continuity.
Is there continuity?
4. The PCB control board is damaged.
Tab. 21 d5 Error codes
38
Supplied By www.heating spares.co Tel. 0161 620 6677
Action
yes go to 2
no B Ensure that ST19 is plugged onto the PCB and the
wires properly tightened on the terminal block.
B Reconnect the boiler electrical mains
B Power ON the appliance
d5? go to 4
yes B Reconnect plug on condensate pump.
go to 3
no B Change condensate pump.
B Reconnect condensate pump.
B Reconnect the boiler electrical mains
connection.
B Power ON the appliance
d5? go to 4
yes d5? go to 4
no B Change or fix wiring to condensate pump.
B Reconnect the boiler electrical mains
connection.
B Power ON the appliance.
d5? go to 4
B Reconnect the boiler electrical mains connection.
B Power ON the appliance.
B Make a note of the altered service function settings.
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change the control board PCB.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
B Restore service settings previously noted.
8 716 115 748 (2009/09)