Is it possible that my worscster 28i combi boiler could be losing pressure due to a faulty heat exchanger.
I have been told i must have a leak but with the boiler losing 1.5 bar of pressure in an hour ,surely the leak would show itself i have been under the floor and found no sign of a leak please help!

M Jeeves, November 2008

my vaillant combi boiler is loosing pressure when heating off, with no signs of any leaks

ryan blake, March 2011

Yes, pressure constantly dropping boiler in use or not,
no leak from pressure relief pipe outside.

M Jeeves, December 2008

do you lose pressure in an hour if boiler is not in use ie no heating being used?

Is it leaking from pressure relief pipe outside?

there are a few pressure problems but have different symptoms,
pressure rising with boiler off, (eg pin holed exchanger)
pressure rising and discharging from pressure relief when using ch resulting in zero pressure when cooled, (eg expansion vessel fault)
constant pressure loss whether boiler in use or not (faulty pr valve not shut or leak)

iain, November 2008