Baxi 100 He Installation And Servicing Instructions page 43

Q
br
r
Ignition
P
PCB
br
N
Sensing Electrode
w
O
Condensate
Trap
g/y
bk
Spark
Electrode
Is there
YES
230V at ignition
PCB connection to
control PCB
(N) ?
NO
Wiring from control
PCB to ignition
PCB faulty.
between 3 and 5mm ?
Set spark gap to 4mm.
Is
YES
there 230Vdc at the
end of the gas valve
lead ?
NO
Replace gas valve lead.
ignition PCB burner on
pin to control PCB
Replace ignition PCB.
M
Control
PCB
bk bk
b bk
b
Dry Fire
bk
b br
Flow Switch
b
r
Gas
Transformer
bk
br br
Valve
Thermistor
g/y
g/y
bk
bk
Safety Stat
S/L N P/F
Mains Optional
Input Pump Feed
Is
fan connection
24Vac across
(L) ?
NO
Wiring from control
PCB to fan faulty.
Is
YES
spark gap
NO
Is
YES
there 230V
(P) ?
NO
14.0 Fault Finding
L
Connector
with
blue label
g br w v b g y o r bk
w
r
b
DC
Fan
Interface PCB
r
Fan Protection
Stat
YES
Check for short circuits
on ignition PCB and gas
valve. If OK replace fuse.
Is
wiring from
ignition PCB to
spark probe OK ?
NO
Rectify wiring.
Replace gas valve.
Is
there 230V
YES
control PCB burner on
pin to ignition
PCB (Q) ?
NO
Burner On wiring from ignition
PCB to control PCB faulty.
Replace fan.
YES
Is ignition PCB
fuse OK ?
NO
Is
YES
sensing tube
blocked ?
NO
Replace
ignition
PCB.
Replace
ignition
PCB.
Unblock
Tube.
Replace
control
PCB.
43