44
6. SPARK WORKS BUT NO FLAME/FLAME FAILS AFTER IGNITION.
IN
Regulated gas
supply to inlet
of gas valve.
Flame
at
burner
Is there a 230v
ac supply to the
gas valve
solenoids, EV1
& EV2 J25 PCB
black/red?
Check the
wiring &
connections at
J25 on PCB, if
ok replace
main PCB.
Rectify gas
installation.
Amber LED
burner on ?
Burner stays
lit, only in
DHW mode.
Are the values of the gas valve
solenoids and the connection
of the spark generator to the
solenoids ok?
Does then flame
light across the
complete burner?
Does the burner
continue to repeat
the ignition
sequence without
locking out?
Replace
front control
panel PCB.
Replace
solenoids
EV1 & EV2
or spark
generator as
required.
Replace the
gas valve &
adjust the new
valve to the
correct gas
pressures.
Check the ignition
pressure (8.0mbar),
if ok check all the
main burner jets
for blockages
boiler works?
Simulate the ionisation
signal with a diode or
replace ionisation electrode
Boiler works?
Check the min burner
pressure, remove a lead
from modulating gas
valve, when boiler
working in DHW mode.
Does the burner go out?
Check the flue for correct installation
possible mixing of products of
combustion with air for combustion.
Replace
main PCB.
Reset min
burner pressure
(4.0mbar).
OUT
No
Yes
No
No
Yes
Yes
No
Yes
No
Yes
Yes
No
Yes
Yes
No
No
No
Yes
No
Yes
Yes
Replace the
ionisation electrode.
41
