The presure guage goes right up to 3 bar when hot water or central heating is on and its stays there - obviously the pressure relief valve has kicked in and water it then being sent out the back of the boiler outside. Please advise

Richard M, January 2009

when you say the diaphram - for the expansion vessel or the hot water small diaphram?

Richard M, January 2009

it sounds like the expansion vessel has lost its charge and needs recharging,you can do this by using a bicycle pump,the pressure to pump it to will be on the vessel,and manufacturers paperwork,if that fails to remedy the fault,the diapghram could be gone,and new vessel will be required.

cal, January 2009