Potterton Puma 80
Have recently had new pressure relief valve fitted, but pressure still fluctuates wildly, when it is very high, water is boiling hot, then boiler cuts out. Have to keep building pressure back up when it is low. Water running constantly from outlet overflow pipe outside, help!

K. Bailey, May 2006

My porterton puma 80e is constantly calling 4 heat even though the switch is on off which i believe is right in the middle.

al, March 2007

Expansion vessel is flat. Open pressure relief valve and find the point at which it stays stuck open. at the back of the boiler, you will find a big disc shaped part behind the boiler on the wall, usually red, with a car tyre style pump up point. leave the pressure relief valve open, attatch a foot pump and pump it to 1 bar. if this is working, you should get some water out of the pressure relief pipe. remove the foot pump and close the pressure relief valve. refil the boiler. problem should be solved. if not, new vessel required.

craig, plymouth, May 2006