53
FAULT FINDING
F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING
isar + programmer -
Installation and Servicing
80 L.....F..... (FLAME DETECTION ERROR)
Check the ignition electrode and associated harness
for: continuity, visual condition
,
position
(Refer to Frame 58).
Are these functioning correctly ?
Check gas valve
wiring for
continuity
YES
Check the detection electrode and
associated harness for:
continuity, visual condition, position
(
Refer to Frame 59
).
Replace as necessary.
If the boiler select (reset) button
is pressed does the boiler ignite
for a short time then extinguish?
Is 200V DC supply available
at the gas valve ?
(see Note)
NO
YES
YES
Is gas pressure available at
the boiler inlet ?
Replace PCB
Check gas supply
and rectify fault
Replace ignition electrode and associated
harness as necessary
NO
Replace gas valve
YES
NO
NO
81 L.....E..... or
H.....E..... (PCB ERROR)
Note.
Due to the wave form of the rectified voltage, the reading will vary depending on the type of meter used to
measure the value (some may measure the possible peak voltage of 339V). In general terms a reading greater
than 150V indicates that the correct voltage is supplied to the gas valve. As an alternative to a meter, a mains
voltage checking device may be used. E.g. an electrical screwdriver or mains tester.
Check spark generator and associated
harness for continuity and visual condition.
(Refer to Frame 60).
Are these functioning correctly ?
Replace spark
generator
YES
NO
Internal fault within the PCB
Replace PCB
Press and hold boiler select
(reset) button for 2 seconds.
Does boiler operate correctly?
Turn boiler off and wait for 5
seconds. Turn boiler on.
Does boiler operate correctly?
NO
NO
YES
OK
YES
OK
Check syphon
and condensate
drain pipework
for blockage
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