26
Upon a demand for Central Heating, (closur
e of the time switch
and room thermostat or programmer, where fitted), the controls
should carry out a set of start up checks, followed by an ignition
sequence. Refer to Section 5.2.
If the control has powered up correctly but does not respond to a
CH demand. Check voltage between pin 2 connector X1A
(orange wire) and pin 2 connector X1B (blue wire). If 0 V ac,
check room thermostat and clock. If 230 V ac, check control for
lockout or blocking codes, (refer to section 8.3), check operation
of the pump.
If room thermostat and clock are OK and no lockout or blocking
code exists and the control is not in anti cycle mode, then
everything should be working correctly, if not contact Technical
Help line: 01926 834834
Note:
Whenever a CH demand is removed,
either by the timer, the room thermostat or by the
appliance’s internal temperature control, an anti
cycle mode is initiated which prevents the
appliance from firing in CH mode for 5 minutes.
Ensure that the control is not in this mode by
switching off at the mains and restoring it after a
delay of 10 seconds.
RESET LOCK-OUT CODES (Display flashes and the er
ror light will be lit)
LED CODE FAULT/EFFECT
REASON
ACTION
●
Check no air is in heat exchanger/CH system
1
Over
heated appliance
Water temperature greater than 105 °C
●
CH system and hot water plate heat
exchanger blockage
●
Check CH ther
mistor
●
Check detection electr
ode/lead
– electrode may require cleaning
●
Check gas supply & pr
essure
No flame
No flame signal on ignition
●
Replace gas valve and/or lead
4
●
Check spark gap
●
Check flue is connected pr
operly
●
Check condensate trap not blocked
●
Check detection electr
ode/lead
5
Flame loss
Loss of flame signal during operation
●
Check gas valve mains lead
●
Check APS
Erroneous APS signal,
●
Check tube connections for blockage/leakage
24
no flame and fan
Missing or defective APS signal
●
Check fan operation
runs continuously
●
Check PCB/X3 connector
●
Check flue condition
●
Check CH flow cir
culation
Water flow failure/
●
Check water pr
essure(> 0.5 bar)
41
flame for a shor
t period
Low water pressure
●
Check pump/lead
only
●
Check expansion vessel
●
Check flow switch
AFTER ENSURING THA
T ALL ACTIONS HAVE BEEN CARRIED OUT PRESS THE RESET BUTTON
8.5
CENTRAL HEATING FAULT FINDING
33
