First post, so please be gentle.
I have the above boiler, 3 years old and, as the pros will know, it is a combi with a 15 litre pressure storage vessel inside. It serves 3 zones, upstairs, downstairs and a conservatory with UFCH.
Before having it fitted, all the existing (12 year old) and new pipework was pressure checked to 4 bar, flushed, etc. It has had regular Fernox, is bled with no airlocks, no leaks at rads and we now have all new floors, so I'm desperate not to go leak hunting.
From day 1, it would happily hold steady pressure at 1.1-1.2 bar but without warning would suddenly drop out and need a top-up every 4-6 months. Now, it can hold pressure for several days, but will drop to 0.0-0.2 bar overnight and trip out. It has had a dose of Fernox F4 sealer and I am confident there are no leaks old or new.
Strangely, the amount I have to top up is very small, only a few seconds on the tap, but after doing so, once running the pressure can shoot up from 1.2 bar to over 2.5 bar and I have to drain a cup-full off to bring it back down again. Once it has gone in to the red zone on the dial and I had to panic a bit.
It is definitely NOT the pressure switch, because the gauge on the front concurs with the electronic reading.
I'm suspecting the boiler, but does anyone have any ideas?
I'm loathe the call out the joker who fitted it 'cos we didn't part on good terms after he hiked the bill
I have the above boiler, 3 years old and, as the pros will know, it is a combi with a 15 litre pressure storage vessel inside. It serves 3 zones, upstairs, downstairs and a conservatory with UFCH.
Before having it fitted, all the existing (12 year old) and new pipework was pressure checked to 4 bar, flushed, etc. It has had regular Fernox, is bled with no airlocks, no leaks at rads and we now have all new floors, so I'm desperate not to go leak hunting.
From day 1, it would happily hold steady pressure at 1.1-1.2 bar but without warning would suddenly drop out and need a top-up every 4-6 months. Now, it can hold pressure for several days, but will drop to 0.0-0.2 bar overnight and trip out. It has had a dose of Fernox F4 sealer and I am confident there are no leaks old or new.
Strangely, the amount I have to top up is very small, only a few seconds on the tap, but after doing so, once running the pressure can shoot up from 1.2 bar to over 2.5 bar and I have to drain a cup-full off to bring it back down again. Once it has gone in to the red zone on the dial and I had to panic a bit.
It is definitely NOT the pressure switch, because the gauge on the front concurs with the electronic reading.
I'm suspecting the boiler, but does anyone have any ideas?
I'm loathe the call out the joker who fitted it 'cos we didn't part on good terms after he hiked the bill