Potterton Puma 100 Problem

[twj42]

Hi

Having a problem with our boiler, an ancient Potterton Puma 100.

It is working, but having a lot of trouble maintaining the right pressure. Pressure is around 1.0 at the start of the day, at 3.0 by the end, with plenty of water run out of the overflow. Plumber came yesterday, pumped up the pressure vessel and replaced the pressure relief valve. Today the pressure is back where it was - rang the plumber his view is the boiler is knackered, and needs replacement.

I don't doubt we do need to replace the boiler sooner or later, but due to an ongoing cashflow problem, I'd really like to delay this until next year, but I will fork out for a new boiler if necessary.

What should I do? Does his diagnosis sound right?

What is a ballpark figure for a boiler replacement (I live in the south east).

Any comments welcome.

Cheers

Tim

 

[ChrisR]

I have yet to see a Puma which had to come out.
A bit like grannies and Morris Minors, they go on for years with a few moans.
I reckon your flexy connection to the pressure vessel is blocked. Shouldn't take a boiler bloke more than half an hour.
See "Boiler Pressure problems" in the faq section.

I think I've got a pic of one somewhere.

 

[twj42]

Thanks very much for that Chris - very helpful indeed, answers all the questions I had, particularly liked the bit about the prv - exactly the issues I am seeing here.

Thanks again.

 

[bengasman]

Drain a bit of water from the system to bring pressure down to zero. Briefly depress the schrader valve on the compression vessel, if you hear a sharp hiss, it is probably the blocked pipe Chris mentioned. If you don’t hear a clear hiss, the ev is dead. Best would be to stick a (tyre)pressure tester on the schrader valve but that might be asking a bit much