Please help with a Potterton 50 Suprima boiler problem

6 Nov 2020
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United Kingdom
Hi, I have a Potterton Suprima 50 Boiler and it stopped igniting, it would try to fire up by running its cycle but then I’d get a flashing red light, it just repeated the process when the reset button was pressed. So I got an engineer to come and look at it. He said a new pcb would probably fix it, so I gave the go ahead, but it didn’t. He said it was likely to be the gas valve, so he replaced it and that didn’t work either. He rang Potterton and they suggested it could be the ignition electrode so he replaced that too, but it didn’t make any difference.

Does anyone know what could be causing this fault before I pull my hair out!!

Not sure if this is any relevance but it works with a Boilermate class a to provide hot water and heating.

Thanks in advance for any assistance!
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How old is the boiler? It does sound like the PCB, it was a common fault on the Suprima, mainly dry solder joints. Was it replaced with a new or reconditioned board?
I seem to remember that the PCB was revised/improved at some point and came with a replacement wiring loom.
Have a google for your board.
The PCBs on these are notorious, was it definately a brand new PCB ? if you are not sure post a pic of the reset button , if it is a new PCB that whole section gets changed
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flashing red can mean the air pressure switch is duff, try getting someone that can actually test stuff before replacing.
Thanks @ianmcd, I got a gas engineer in and he bought it from the merchant so I’ assuming it was brand new. The new board’s light, reset button and temperature knob look exactly like the previous one, I’ll post a photo as soon as I’m able.

If I remember correctly, the engineer released the cradle in the boiler, removed the pcb old box and then put the new box in. So I assumed it would be the latest version.
He is a very unlucky engineer then to have a pcb, a gas valve and ignition lead fail on him and now something else has failed, who would have thought.:whistle:
@picasso, my thoughts exactly but what do you do?!

@ianmcd it looks to me like the new one then, as it had the connectors coming out of it. Photo attached in situ. Thanks for your help!


  • Potterton Suprima 50 new pcb.jpg
    Potterton Suprima 50 new pcb.jpg
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@picasso, my thoughts exactly but what do you do?!

@ianmcd it looks to me like the new on then, as it had the connectors coming out of it. Photo attached in situ.
Yep that is the new one, you can tell by the reset button, but they are extremely flaky, I have had a few boilers that eat those PCBs in months , terrible design, horrible boilers
Hi @BoredSeb, @ianmcd and @picasso, I hope you're all well. As you responded to my cry for help, I thought I would update you on the situation. My boiler has now been fixed, it turned out to be the flow switch which has been replaced.

Thanks for your help!

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