C&M 24 - Fault Finding Chart Part 2; Flame Detection and Gas Solenoid Checks; Combustion Chamber and Airflow Diagnosis; Ionisation Probe and Control Board Diagnosis

14
FAULT FINDING CHART Part 2
Replace control PCB
Can you see the
fl
ame on the burner ?
Replace gas section assembly
Do you feel air draw
-
ing in at the air inlet ?
Do the gas
solenoïds energise ?
Check that air inlet pipe, ven
-
turi, fan, air/gas pipe or burner
are free of dust and not blocked
Purge the gas pipe and press
on reset button
Does the burner still
alight ?
Does the red LED
light and -3 displayed ?
Replace control PCB
Replace display PCB or control the
connection between the 2 PCBs
No
No
Yes
No No
Does the orange
LED light ?
No
Yes
Yes
Yes
Yes
No
-3
Replace display PCB or control the
connection between the 2 PCBs
Is the combution
chamber full of conden
-
sates ?
Yes
Check ionisation
probe
No
Ok
Drain and clean combustion cham-
ber, siphon and drain pipes
Yes
Replace the ionisation probe
No
Wait until the return pipe
become hot then reduce CH
temperature to minimum
Does the orange
LED light ?
Replace control PCB
Yes
The boiler is OK
No
The heating outlet
pipe temperature rises