Supplied By www.heating spares.co Tel. 0161 620 6677
FLOW CHART 1: START/POWER UP FAULT FINDING
FLOW CHART 2: IGNITION SYSTEM FAULT FINDING
START
Gain access to boiler control
box then switch on electrical
supply
Is 230v present
across pins 2 & 3 ?
Is green LED
illuminated ?
Is the pump running ?
Is the fan
running ?
When fan stops is
red LED illuminated ?
Replace fan
Is 230V present
accross pins 12 & 13 ?
Check overheat thermostat &
re-set if necessary
Check fuse F1 2A
Check fuse F2 1A
If blown replace
If fuses OK replace PCB
Re-check mains supply
including fused outlet
Is APS in closed
position ?
Replace APS
Replace PCB
Check pump flow switch
replace if faulty
Start up
completed
YES
YES
YES
YES
YES
NO
YES
YES
NO
NO
NO
NO
NO
YES
NO
On power up the PCB should
power the fan and pump for
around 15 seconds to prove the
APS, pump flow switch and
overheat stat.
A fault condition will be
indicated by a steady red LED.
Pump ‘ON’
Primary flow switch
contacts closed
START
PCB should carry out APS
pump flow & overheat stat
checks. See Chart 1
Is red LED illuminated ?
Is APS operating correctly ?
Are sparks present at the
spark electrode ?
See start up checks in
Flow Chart 1, above
Check wiring and tubes
replace if necessary
Replace PCB
Does burner light ?
Is 230V d.c. present across
pins 10 & 11 ?
Replace PCB
Does burner remain lit?
Check gas valve
Replace if faulty
Check detection electrode
Replace if necessary
Ignition sequence
complete
NO
YES
NO
NO
NO
NO
NO
YES
YES
YES
YES
NO
Check 230V present across
pins 14 & 15
replace if necessary
If fuses OK replace PCB
Check Pump Rotation
Check Pump
Running
Check Polarity
ie. is Live and Neutral to
boiler crossed
NO
Check spark gap
YES
Note:
If there is air in the system or boiler the lack of water flow through the boiler will cause the LED to be illuminated. Bleed all air out of the pump and system
and turn off electrical supply for 10 seconds before starting the ignition sequence again.
27
Note: An anti-cycle timer is built into the control system. If the appliance does not light,
wait a minimum of 4 minutes before restarting the boiler.
