
Supplied By www.heating spares.co Tel. 0161 620 6677
32
221473B
3 Fault Finding
Diagram 3.5
5064
Press reset switch
wait 15 seconds between
attempts. Are there sparks
at electrode ?
Does burner light ?
Does boiler go to lockout
after
≈
10 seconds ?
Is burner
pressure
at full DHW.
Reduce DHW
water flow,
does burner
modulate.
Turn off hot tap,
does burner
extinguish.
Faulty main PCB, replace.
Is there 230V ac on pump ?
Faulty main
PCB, replace.
Faulty pump, replace.
Turn on CH
demand, does
pump operate.
As heating
system
becomes
satisfied does
burner pressure
reduce ?
Normal
operation.
Faulty main PCB, replace.
Does the DC voltage
across the modureg
reduce.
Faulty main
PCB, replace.
Faulty modureg, replace.
Isolate supply, Check
dimensions of sense
electrode and condition of
lead. If ok replace CVI
ignition unit ?
Check
dimensions of
spark electrode,
if ok replace
CVI gas valve
unit.
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
A
B
C
D