Pressure gauge keep creeping up to 2bar.

[John_]

Hi all, wonder someone can shed some lights to this, the gauge on my boiler (Valliant turbomax combi) keep increase to around 2bar. I bled the radiators and drain out some of the radiators water brought the pressure down to under 1bar but when the heating comes on for about 1 hr the gauge shows nearly 2bar. Tried this a few times, still the same. Could this be an expansion vessel fault in the boiler?

[Howsie]

Up to 2bar isn't a problem. The water expands when it's heated and its natural to see a pressure increase.

If it continues to increase it would seem that you're filling loop is connected and letting bye.

[grahamgas]

If the exp vessel was faulty, or needed recharging, then the pressure would normally shoot up quite rapidly.

[JCplumb]

If the filling loop was letting by, the system pressure would also rise when not in use, so easy diagnosis for that one - turn heating off, let it cool down, is it still rising?

[dontknowitall]

If you remove the filling loop you'll soon know whether it or the fittings around it are at fault. If it's not letting by then it's most likely to be the expansion vessel.

[John_]

Thx guys. Will recheck to see if it's letby although that was the first thing I checked and the valve was shut.

[dontknowitall]

Aye - the valve may well be shut but it might not have isolated the water - if you remove the filling loop you'll see if it's letting some through.

[Whn1]

Does it stop at 2bar?

[John_]

Can't remove filling loop
as it is built in. Yes it stop at around 2 bars - u got some idea?

[Howsie]

How many rads do you have?

[Howsie]

Stops at 2 bar, no problem.

[John_]

10 rads.