my boiler is losing pressure and no one can get to the bottom of it !!
overnight the pressure drops to virtually nothing with the boiler off.
I refill it to one and a half bar then switch the boiler on at this point the pressure starts to fall and it sounds like you can hear air escaping i refill it again and it fires up, then a short while later the pressure goes up to about 3 bar on its own. the heating and water are ok and i can't find a leak anywhere.
when i switch the boiler off at night the next mornin the pressure has dropped again. Can anyone please help me !!

NIGEL BROOKES, February 2009

yep 9times out of 10 the exp vessell needs replacing.

robbo, March 2009

expansion vessel may req recharging or is faulty;check pressure relief valve outside for dripping water;

daz, February 2009