My boiler is running out of pressure, there is no leak anywhere, as soon as I refill the boiler, the pressure gauge drops straight back down within two minutes, there is hot water coming out of a pipe from the boiler outside wall, although there is no pressure in the boiler it is working ok central heating and hot water. Any advice would be greatly appreciated.

Cheers Tony

Tony, January 2010

try this
check the expansion vessel contains air, may need re-inflating to 1 bar max pressure with a car pump (test with no mains pressure in system)

now repressurise l the water on the central heating side back up to 1- 1.5 bar max pressure cold

wirecutterman, January 2010