glowworm xtramax - "no gas fault"

[cocodave]

as stated this boiler is flashing the warning triangle and showing the spark symbol, the manual says this is "no gas fault"
instructions are to
turn off
rectify gas fault
turn on

the house has gas as the hob works downstairs, gas is also switched on at the appliance and at the test nipple.

when switching all off and back on the "3 way valve motor" is heard to turn and the fan spins very slowly for a bit.

the fuse on the pcb is not blown - checked for continuity

checking the last 10 fault codes
20 = pcb / communication error
14 = 3 way motor
13 = pcb fault
4 = no gas
4 = no gas
4 = no gas
4 = no gas

as there is mention of the pcb at least twice do you think that it has failed, the faults have no date/time stamp, so cannot confirm they are all from same date or from the life of the appliance (5 years)

at £154 + vat and postage i`d like to know that i was making a good educated..... guess at replacing the pcb.

any one got any experience they can assist with fault finding this unit

 

[Agile]

It does sound as if the PCB is not operating correctly.

However, before replacing the PCB, I would check that the gas valve is not being powered and that any condensate trap interlock is not compromised although I dont think its a condensing boiler.

As you dont tell us the exact model its difficult for me to make any more specific guesses.

Tony

 

[cocodave]

thanks for the advice so far Tony.

gc number is 47-047-15

reading the manual there was reference to voltage checks on the pcb have two manuals one came with the boiler and the other i downloaded, and they are different....
was short of time before went to work to check these measurements.

230v at H8.1 and h8.2 looks like on off switch to pcb
24v//33max DC at b2.4 and b2.7
15v at b2.4 and b2.2
5v at b2.4 and b4.2 mentions display

the manual that is downloaded shows "J" terminals rather than "B"`s so cannot look at the schematic to trace back but think 24 and 15 will be fan and gas valve.

shame they dont put in a functional flow diagram to follow on this model in the manual..

as the pcb price is soooo close to the one off cost to call out british gas then it seems best policy to go that way but it would be nicer to know the answer and how to confirm it.

 

[ollski]

I had exactly this the other week and wasn't too sure if it was the main pcb or honeywell ignition pcb but suspect it was the latter. If you can wait until Monday I can let you know which one it was when I ask my mate who fitted it.