Hi Folks hope you can shed dome light on this for me...

Combi 24 cdi Pressure build when off

Problem began with a leak
After consulting manual and stripping down boiler as req'd found a bad leak at the Gas to water Heat exchanger. Bought a set of O Rings (original parts)
lubed with silicone grease and refitted.
All was fine for a day or two and then it leaked again ,not too much but concerning.


Realised a pressure build was going from 1.5 to 3 bar overhnight ..... !Boiler Off!.

Tested Expansion Vessel for Air or water and got air
havent pressure tested it yet

Assume not possible to leak accross filling loop
as it a "Insert the T bar type"

grom-it, November 2008

I would like to amend the above

I infact mean NOT when the boiler is !off!

But when the boiler is on but no hot water being drawn off and no central heating switched on

grom-it, November 2008