FAULT FINDING
BOILER BURNER
SYMPTOMS
CAUSE
REMEDY
SWITCH ON
- nothing happens.
No power to unit.
Check mains supply, time clock,
external thermostat.
No output from PCB
Fuse (F2) failure.
Check for wiring failure
to PCB, replace fuse,
If fuse fails replace PCB.
Boiler thermostat off.
Switch on.
Faulty thermostat.
Replace thermostat.
Fuse (F1) failure.
Check for component
failure e.g. glow plug
and replace fuse.
FAN NOT RUNNING
Fault with air pressure.
Check pressure has not
been tampered with.
Sensing tube positioned
correctly, change pressure
switch.
PCB fault.
No power to fan, change
PCB.
Fan unit fault.
Change fan.
FAN ONLY
- Fan and glo-plug energised/
Pilot solenoid failure.
Replace pilot solenoid.
No pilot/Lock out/ Glo-plug
PCB fault.
Replace PCB.
De-energised/Fan continues
Pressure switch not
Clear blockage or
running.
operating.
Replace pressure switch.
-Fan, glo-plug, pilot solenoid
Thermocouple fault.
Replace thermocouple.
Energised/Pilot flame/No main
Main solenoid fault.
Replace main solenoid.
solenoid.
PCB fault.
Replace PCB.
-Solenoid and glo-plug de-
energised/ Fan runs on/Lock out
PCB fault.
Replace PCB.
light.
FAN and GLO-PLUG on
CONTINUOUSLY
- Fan and glo-plug on/pilot
PCB fault.
Replace PCB.
solenoid does not open.
PILOT BURNER DOES NOT LIGHT
- Glo-plug energised/power to
Pilot solenoid fault.
Replace solenoid.
pilot but does not open.
Pressure switch fault.
Check setting of pressure switch.
Replace pressure switch.
Air lock in pilot oil feed pipe.
Check oil pipe rises steadily over
whole length.
Glo-plug not working.
Check Volts to Glo-plug(Approx 1.5v.) Check
contacts on Glo-plug terminals.
Replace if required.
Transformer fault.
Check Volts In/out. Replace if
required.
Wick displaced.
Check wick in burner replace if
required.
Glo-coil touching wick
Adjust wick to be 2-3mm clear
of glo-coil
Long timer fault.
Replace PCB.
Short timer fault.
Replace PCB.
PILOT FLAME ONLY
- Lack of oil to main burner
Air lock in oil feed pipe.
Remove air lock/ensure gradual rise
on pipe-work
No power to main solenoid.
Replace PCB.
Main solenoid fault.
Replace main solenoid.
LOW AIR PRESSURE FROM FAN
Air adjustment cover on fan duct
Reset air adjustment cover on fan
set wrongly.
duct.
Wind box leak.
Replace gasket.
Fan speed too low
Replace fan unit.
NO FLAME SENSING
- Goes to lockout
Thermocouple fault.
Replace thermocouple.
PCB fault.
Replace PCB.
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