My combi Boiler has been losing pressure regularly. I've been topping the boiler up using the filling loop, only for the pressure to drop down to zero again. However the pressure hasn't dropped now for 2/3 days, but shows as over 3 bar. Is this bad? Why do I now have too much pressure in the system and how do I reduce it?

Rob French, November 2007

the pressure in my boiler used to last 4-5 weeks, its starting to empty over night now any suggestions thanks. Stuart

stuart clarke, December 2010

it sounds like the pressure release valve is faulty (and now seized up?). they're normally quite cheap (less than £10) and easy to replace. If it's like mine it'll lead out from the bottom of the boiler to the outside wall via a pipe and will probably have a manual cap (red) you can turn to release pressure if too high.

Ric, November 2007