Boiler pressure high when heating & hot water is on?

[wild nomad]

Hi there,

Recently had a query from a customer as below:

Boiler has recently been showing high pressure when hot water or centralheating is on, leading to occasional lock outs.”

The boiler is a Potterton HE Powermax. Was thinking it may be a blocked primary heat exchanger?

Anyone have any other ideas of what it might be? I am Gas Safe Registered but I don't think it's showing up on my profile at the mo. Ask Croppie about that 🙂
Reg No: 573285

Thanks in advance 🙂
Mike.

 

[solutions]

When you can post in the gas safe private forum I know there will be lots of help regarding your question. But you wont get any on the open forum as we cant tell who might attempt the repairs or fault finding that shouldnt.

 

[solutions]

I would however also suggest you try and give the actual lockout or error the potterton is showing. High pressure alone doesnt cause lock outs.

 

[wild nomad]

When you can post in the gas safe private forum I know there will be lots of help regarding your question. But you wont get any on the open forum as we cant tell who might attempt the repairs or fault finding that shouldnt.

Thanks for the advice. Exactly how do I post on the private forum... and where is it?

 

[Dotty]

Go to the GSR public forum and look near the top.

But don't worry too much for now as I'll be moving this fred.

Oh, and Arms access sorted too.

 

[solutions]

Once you have your gas safe tag (contact admin, Redsaw I believe can help there) you will find it in the subforums in the gas safe public forum.
Forum tree goes:
Plumbing forums / Gas safe registered forum - public forum / Gas safe registered forum - private forum

 

[wild nomad]

Go to the GSR public forum and look near the top.

But don't worry too much for now as I'll be moving this fred.

Oh, and Arms access sorted too.

Cheers Croppie, that was quick!!! Ignore the PM I just sent you asking the same questions you have just answered 🙂

 

[wild nomad]

I would however also suggest you try and give the actual lockout or error the potterton is showing. High pressure alone doesnt cause lock outs.

Yes, no fault code was given to me. I'll find out soon enough I guess. I was just wondering what others thought it might/could be. I was thinking blocked primary heat exchanger causing the pressure to rise when the boilers on and then over heating causing lock out?

 

[solutions]

Ok Mike now your original post is safely behind closed doors we can begin.
If the boiler has excessive increses in pressure during heating of any kind then my first port of call would be the expansion vessel. Is it charged? Has it failed? Is pipework to it blocked? If the boiler during demand is exceeding 3 bar is the prv opening? Are there signs it has been doing it for some time? Is the filling loop in place? Is the filling loop set inlet valve/ valves passing?
If the pressure is exceeding 3 bar and system water is being dumped then likely boiler starts running dry and locks out on low water content / no flow or overheat due to no water thats my bet.

 

[London Gas]

Also is the water pressure constantly needing to be topped up after it cools down? It sounds like an expansion vessel to me also I would check this first, check the data badge and check if the pressure is correct and if the diaphragm has split.

 

[REDSAW]

been out playing poker 😉

 

[AWheating]

been out playing poker 😉

did she enjoy it?