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Michael29068

Gas Engineer
Nov 23, 2010
39
4
8
Hi, I am looking at a Potterton Profile 50e on which initially the fan was cycling on start up. I changed the Pcb and this sorted the cycling problem however I cannot get it to start sparking.
I have checked air tubes and restrictors to Air Press Switch and also Air Press Switch is changing over. Door seals are ok and connections onto pcb are ok. I have also changed ignition lead and electrode, but it will not spark for me. I have also tried another Pcb.
Any suggestions anyone.
 
Is there power at the pcb? And if yes is there power on the A.P.S and Fan. If not check your wiring on the PCB.
 
Check all the connections on the board. If necessary go through every wire again. Is it clicking at all? Is there power at the gas valve?
 
Surely if there is power to the fan and aps. I would be checking my wiring on the new board. Sounds like either APS or board. Check APS tubes are on the correct way around and pcb has been wired correctly and fuses are ok if there is any on the board.
 
Pretty sure a profile wouldn’t spark without the case on even with a new APS,sometime trying to simulate enough pressure to operate the switch is not exact enough & trying to see the spark with the case on can be hard to confirm.Try disconnection the HT lead from pcb an using an insulated screw driver near by weather it’s bridging a spark to that. If you’ve got continuity through your lead then there is no reason it should not spark at pilot assembly. Could be wrong but maybe take out pilot injector an check this is not blocked
 
Pretty sure a profile wouldn’t spark without the case on even with a new APS,sometime trying to simulate enough pressure to operate the switch is not exact enough & trying to see the spark with the case on can be hard to confirm.Try disconnection the HT lead from pcb an using an insulated screw driver near by weather it’s bridging a spark to that. If you’ve got continuity through your lead then there is no reason it should not spark at pilot assembly. Could be wrong but maybe take out pilot injector an check this is not blocked
thanks for your replie





Thanks for your replies, I have not got back to this boiler yet but I have disconnected HT lead already and checked whether it is bridging a spark and it is not, as for the pilot injector being blocked I am not not getting a spark at the electrode to light the pilot even if it is clear. I seem to get the APS to change over when the fan runs.
 
Pretty sure a profile wouldn’t spark without the case on even with a new APS,sometime trying to simulate enough pressure to operate the switch is not exact enough & trying to see the spark with the case on can be hard to confirm.Try disconnection the HT lead from pcb an using an insulated screw driver near by weather it’s bridging a spark to that. If you’ve got continuity through your lead then there is no reason it should not spark at pilot assembly. Could be wrong but maybe take out pilot injector an check this is not blocked


You’re right. I wasn’t thinking. It’s a positive pressure case isn’t it.
 

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