Potterton Combi 80: electrician or boiler engineer?

[ladyfrombleakhouse]

This 7 year-old boiler dead as dodo last Thursday - no heating, no hot water. Water had been very hot. Recent banging in pipes and 2 lockouts had responded to resets until last week when, for first time, even the mains light had gone out. Corgi plumber came Sat. Said boiler looked fine - no mains light indicated no electrical supply to boiler and told me to get electrician. E came on Monday, put in new wall switch and cut cable to bypass old, non-functioning timer - put new fuse in boiler. Got whole system working. Great! Until 8 am next morning when whole system ceased to function again. Trying to avoid calling Potterton engineer (at £259). Will call their technical support people but thought this forum could well be more knowledgeable and honest! Afraid am not DIY goddess!

Reading these posts, I wonder if my 2 leaking taps could be source of problem, but my plumber is reluctant to come to fix them, and says call back the electrician (mains light gone off again). Electrician says call in Potterton. Am trying to gen self up a bit so am not easy game for rip-off! Any ideas please as to cause and next step? It's been a cold week!

 

[ollski]

I think I'd be tempted to check the pump with the banging noise and overheats....get yourself a good heating engineer.

 

[Agile]

I cannot guess at what is the fault on your boiler as there are several possibilities. A jammed hot water flow switch is one possibility. A faulty PCB is another.

When it is working if you have ANY dripping hot taps they will stop the boiler from working on central heating at all.

I also think that you need a boiler engineer instead of a plumber!

Tony Glazier

 

[ChrisR]

Dripping hot taps will always stop the CH working properly on one of these boilers. There's a wee tap under the boiler you can use to stop the HW with totally which proves that one. Anyone who mends boilers much would know that.

That boiler has a few other tiresome habits, like leaks which get to the electrics, and dodgy printed circuit boards, sticking switches, which can often lead to intermittent behaviour. If the right sort of bloke were standing at the boiler, he'd diagnose the usuals in the first couple of minutes. Trouble is, getting the right sort of bloke.

There's always a chance of the obscure, but common problems have common causes.