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SECTION 4 - FAULT FINDING
4.10 ‘F2 OR FN OR LN’ - FLAME LOSS
Does the boiler ignite for a short
time and then extinguish?
YES
YES
Is the Gas Pressure available at
the Boiler Inlet (35 ±0.5 mbar)?
Check if condensate pipe is
blocked. Check if flue is blocked.
Replace as necessary.
Is the top flue manifold seal present
and correctly fitted. ?
NO
NO
Check gas supply and
rectify fault
NO
YES
Is 24Vdc supply available at the
Gas Valve while the flame is on?
YES
Check spark generator and
associated harness for: continuity
and visual condition. (Refer
to Section 3.13) Are these
functioning correctly?
YES
Check ignition electrode and
associated harness for: continuity,
visual condition and position.
(Refer to Section 3.12) Are these
functioning correctly?
YES
Check siphon and condensate
drain pipe work for blockage and
rectify if necessary. Boiler now
working OK?
Check wiring from gas
valve to PCB for continuity.
If the wiring is OK then
replace the PCB
NO
Replace Spark Generator
and Harness as necessary.
NO
Replace Ignition
Electrode and
associated harness as
necessary
NO
Replace Gas Valve
Re-fit correctly or replace
NO
4.11 ‘F3’ - FAN FAULT
Does the wiring from the Fan to the PCB have
secure connections at both ends and has not
deteriorated? Does the wiring have continuity?
YES
Rectify Wiring &
connections
Is there 230Vac at the Blue and Brown connections
to the 3 way connection on the Fan?
NO
Replace PCB
Replace Fan
NO
YES