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19.
FAULT FINDING FLOWCHARTS
Should a fault occur, the boiler will shut down and these error codes will be displayed.
IGNITION LOCKOUT
OVERHEAT LOCKOUT
FALSE FLAME LOCKOUT
YES
YES
YES
NO
YES
YES
YES
NO
NO
NO
Check siphon and condensate drain pipe
work for blockage and rectify if necessary. Is
boiler working?
Check routing and integrity of internal boiler
wiring.
Check the gas supply
Check wiring connection from gas valve to
PCB for continuity. If the wiring is OK then
replace the PCB.
Replace the pump, the reset the boiler.
Replace the gas valve
Replace board and harness as necessary.
Replace PCB and associated harness as
necessary.
NO
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
NO
Check the pressure control pipe between fan
and gas valve for continuity, visual condition,
replace as necessary. Is boiler working?
Check the Flow & Return thermistors.
Check resistance using a suitable multi-meter
connection across the thermistor’s terminal
pins
RESET PROCEDURE
To reset the boiler,
press the reset button.
Is the gas pressure available at the boiler
inlet (>18mbar)?
Fill & vent the system & open all isolation
valves, then reset boiler.
Check routing and integrity of the internal boiler
wiring is working OK. Check condition of the Flame
Sensor Electrode and replace if necessary.
Is approx 24 VDC supply available at the
gas valve?
Check that the pump is rotating freely. Is the
differential now below 20°C?
Replace flame detection electrode.
Unplug the gas valve. Is resistance between
outside pins 114
Ω
Reset the boiler.
Check board and associated harness for:
continuity and visual condition. Are these
functioning correctly?
Check ignition and associated harness for :
continuity visual condition and position. Are
these functioning correctly?
Replace the Gas Valve.
If the boiler is reset does the boiler ignite for
a short time and then extinguish?
Is the boiler & CH system filled with water
and all isolation & radiator valves open?
Reset the boiler. Is the boiler working?
Check the detection electrode and associated
harness for: continuity, visual condition and
position. Check if the condensate pipe is
blocked. Replace if necessary.
Is the Flow/Return differential across the boiler
in excess of 30°C?
Remove ignition lead and earth tag. Is
there continuity between the terminal pins
connected to the electrode?
FAN FAULT
YES
YES
Replace the Fan.
NO
NO
Rectify wiring & connections
Replace the PCB.
Does the wiring from the fan to the PCB have secure connections at both
ends and has not deteriorated? Does the wiring have continuity?
Is there 230Vac at the Blue Brown connections to the 3 way connection on
the fan