What is the pressure supposed to be when the boiler is at rest.My water keeps falling below 1/2 a bar and I need to refill to around 1 bar.When the cetral heating is on it reaches aound 1and1/2 bar.My central heating works fine but Im concerned because there are no leaks from the rads.Is the boiler emptying itself or am I worrying for nothing.

Steve Lloyd, March 2011

expansion vessel will be flat or pressure relief valve passing - check the pipe out the wall at the base of the boiler and see if it drips when heating is on after 5 mins. if so needs pumping up with a foot pump

craig, March 2011

1 bar cold is fine rising to 1.5 bar when on is normal if your losing pressure it could be a leak under the floorboards

heatmate, March 2011