Any help is appreciated.
I came home from work last night and the CH was not working. The water pressure was at 0.5 bar and there was water on the floor below the boiler.
I refilled the system to 1.0 bar and the boiler fired up. I then had a constant drip of boiling hot water coming out of the reduced pressure zone valve as the heating was running. When the heating went off it turned into more of a trickle and the pressure went down to zero. I had to look in the manual to find out what the leaking part was. It is definitely not the pressure release valve as this discharges outside.
For my second repair of the night I got the foot pump out the van and tried the expansion vessel. The air pressure was at zero and I inflated it to 0.5 bar as per specs in the manual. Water pissed out of the RPZV as I added the air and then pissed out water again when I repressurised the water side. All seemed well and the boiler worked fine until I went to bed. This morning the pressure was at zero again and the floor was wet through.
The only two things that are different with my combi to normal installations are
1) it is not used for HW (it will be next year) 2) it has not been connected to the main cold water supply for the 2 years it has been installed. It was filled up 2 years ago when installed and has never lost any pressure.So what is the faulty part, the expansion vessel or the RPZV?
Cheers
Adam