Potterton Puma 100p HW & CH make boiler switch off, help

[Eastcote_Bloke]

Potterton Puma 100p, about 10 yo.

Had pump replaced last year.

The main problem with it is when the CH is on and someone turns the hot tap on, hot water comes out no problem, however when the tap is switched off the boiler makes all sorts of boiling-up noises and switches off the pilot. The boiler then sits there with the fan running at maximum.

There is a secondary problem where for example despite the pilot being lit all night (ok I don't stay up to check *all* night but did check once or twice) the boiler comes on with the timer but then goes out pretty much immediately. "Brrr... " says bloke. Wife is somewhat more explicit.

A friend (heating engineer, CORGI reg., but not a Puma specialist) looked at it and it's defeated him, he did replace the diaphram thingy and the pump - sadly no effect on the symptoms. I suspect he views our friendship slightly differently now, a pity...

So could it be low-pressure of the inlet water? We have an old lead pipe from the street to the house.

Could it be aliens from the planet Potterite have taken up residence?

Am open to idea of replacing, but if it can be fixed...!

Your thoughts would be very welcome.

EB

 

[bengasman]

Yes, it can be repaired. Pumas are know for problems with diverter and pcb. Could be coincidence, but I have yet to find the first puma that was not full of sludge. This is one boiler I would recommend replacing if you can afford to have it done properly, but repair if replacing would have to be a budget job

 

[ChrisR]

however when the tap is switched off the boiler makes all sorts of boiling-up noises and switches off the pilot.

Standard simple puma fault, the tap water flow switch is sticking on.

the boiler comes on with the timer but then goes out pretty much immediately.

main burners could be starving the pilot, which puts the boiler out.
Needs a service.

diaphram thingy

Eh?

Easy boiler to mend - hang on to it..

 

[Agile]

Any competent boiler engineer who deals with the range of common installed boilers will be familliar with your model and fault and will be able to diagnose the generality of the fault over the phone.

Last one I went to was a seized communicating rod so no parts were needed.

One wonders which planet your "friend" has been working on for the last 10 years!

Tony