another potterton problem

[skcam72]

hi, great site.
i've done a search but not quite found the answers i need so any comments appreciated. i have an appx 12 year old potterton profile ng 60 which is in need of help getting started. from what i've read it seems a common complaint but the boiler struggles to ignite often taking 20+ turnover before firing up. called the engineer and he cited the pcb as the reason but has quoted me £250 + vat to supply and install. having searched ebay etc it seems these parts range significantly in price so just wanted some expert opinions on A) does the fault sound like PCB and if so B) whats a fair price to pay in london to supply and fit if you don't mind me asking.

many thanks
stuart.

 

[meldrew's_mate]

In short the ignition sequence is
1. fan
2. air pressure switch (usually within 10 seconds)
3. pilot and spark
4. pilot flame detection
5. main burner energised.

If the fan starts but fails to start the sparking, or takes longer than, say 30 seconds this could indicate APS fault or fan failing to reach proper speed as the likely faults.

If the sparking starts and takes along time to light the pilot this may indicate a pilot in need of cleaning or poorly adjusted pilot (boiler service req'd).

If the pilot lights AND the sparking stops, but the main burner takes a long time to come on a gas valve fault is suspected.

Combined with all of these is the possibility of a PCB fault, but armed with these facts you may be able to narrow it down before shelling out about £110 +VAT (last time I looked) for a new PCB

If you're in London perhaps Agile would be better able to advise on labour rates, I think he does a fixed rate + parts.

 

[Agile]

We charge a fixed price diagnostic fee of £84 plus the cost of parts in our local area ( N, NW or W London )

However, British Gas apparently do an inclusive parts and labour for £132 or £142 depending on whether you buy gas from them and if anything has actually failed as opposed to just needing cleaning or adjustment this might be a cheaper option.

Unless its the fan we could probably match the BG price!

Tony Glazier

 

[skcam72]

thks for quick feedback. i had the boiler serviced 12 months ago. from what you have said it could well be the fan. The fan starts but only after many 20+ attempts can i see a spark, when the spark appears then the boiler ignites fully and works for a period of time (say 5-10 mins) before shutting off and starting again with bursts of fan turnover. so could be fan and PCB?

 

[ChrisR]

If the fan starts it's probably not the fan, though it could be fluffy or running slowly.
If the fan wasn't removed when the boiler was serviced, it wasn't serviced!
I can cover SW/S London