Issue with boiler loosing pressure :/

shaiboyuk

Hi all,

First time post, so go easy on me

I'm having issues with our boiler that was installed in 2012 (potterton promax combi he plus). It keeps loosing pressure and the overflow outside seems to be soaking the wall. I took the front panel off the boiler today, and found the pressure release valve and opened it fully and closed it, to see if it was stuck open to release it and close it fully.

It seems to be holding ok at the moment, but wondering if the PRV could have gone and needs replaced? or I've read it could be the expansion vessel needing air?

Any help gratefully appreciated as don't have the money for a engineer if its something I can sort myself.

Thanks
Paul aka shaiboyuk

Crinkmeister

Sorry, but you should not be messing with gas appliances.

Ectophile

If it's leaking down the wall, and simply losing pressure, then it'll be the PRV.

The sign of a failing expansion tank is that the pressure shoots up as the system warms up. When it hits the maximum pressure, the PRV opens to relieve the pressure. When the system cools down again, the pressure will be too low, because of the water lost.

However, if the PRV is called on too many times, then it can start to stick open. So watch the pressure when the system warms up, as you may have both problems together.

macman

Once it's lifted, they often won't reseat properly and need changing.