The non-return valve could be at fault - put pressure up to 1.5bar and then open/run a tap and/or flush a WC if pressure drops it's the non-return valve failing.
Brian
September 2006
they can drop very slightly over a period of months. if your loosing a lot very quick you have a leak some where check all your radiators for leaks.
hi-spec plumbing
September 2006
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.