Potterton Performa 28 pressure problems

[Thirsty]

Help!!

I've recently fired up the central heating to check it all works before the cold sets in. All worked fine, radiators bled, system topped up to get the pressure back up to just over 1 bar.

Shortly after doing this, I noticed that the pressure kept rising whilst the heating was on. It got to a point deep in the red zone that I thought it prudent to switch it off to let the pressure drop.

In the last couple of days whilst waiting for someone to diagnose the problem, I have used the boiler in this manner; switching it off when it reaches about 3 bar.

Yesterday, I was getting the flame ignition warning light flashing so I followed the manual by using the reset switch. The boiler fired for a couple of seconds before cutting out again. After repeating a couple of times, there is now no ignition and a strange electrical burning smell coming from the PCB in the drop down panel.

I'm pretty sure the PCB will require replacing but could this have been the cause of the pressure problems?

 

[ismellgas]

pressure rising is an expansion vessel problem. hopefully it just needs pumped a bit. If the pressure drops while its cold i'm assuming that would rule out the filling loop..

 

[Thirsty]

Thanks ismellgas

The pressure does drop to between 1/2 and 1 bar as it cools. Excuse my ignorance but what does pumping the expansion vessel involve?

I neglected to mention that the pressure release overflow pipe outside is weeping constantly. Not a lot, about a couple of thimbles full over 24 hours. Is that likely to be a seperate issue altogether?

Thanks for your time!

 

[kevplumb]

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