H/w expansion vessel

[wil]

I need advice but I'm not a plumber, I'm a joiner.We have a house in Portugal and last year had c/h installedwith new 200litre h/w cylinder. The h/w system is non vented and the cylinder is also heated by a solar panel. A month ago the 7 bar pressure relief valve started to leak when the guage on the cylinder read 55 c.I got the plumber to come back( after a while) and he simply adjusted the incoming pressure control valve. Its still leaking and i cant contact him, ive checked the expansion tank( potable water type) and its reading zero, i also pressed the shrader valve and no water came out so I'm thinking somehow its lost pressure. I have a basic knowledge of plumbing so I'm going to attempt to reflate the vessel myself or if its jiggered, replace it.on the incoming c/w supply there is a pressure control valve with a blank fitted for a guage. I have the guage and there are isolation valves either side so if i fit the guage and get the incoming pressure do i inflate the vessel to equal that pressure and why would this vessel lose its pressure or fail so quickly? In the summer here when it was 40c outside the water temp in the cylinder was often nearing 80c and we had no problems. Any advice anyone can offer would be greatly appreciated

 

[Best]

Hello Wil. Sorry you can't really get advice on touching unvented cylinders on this forum as it is illegal to install or service them in UK without a G3 qualification. The unvented units are potentially dangerous if not installed or serviced correctly, so much the same as gas work, no advice involving working on the appliances can be offered on open forums.
The plumbing laws in Portugal might be different.
The unit might have a 25 year guarantee and a minimum of 1 year on parts, so if I were you I would get a local plumber to fix it for you.

 

[Riley]

Good advice. Potential bombs if done wrong. Get a qualified engineer

 

[wil]

Many thanks, i didnt realise you had to be qualified in the uk, from what you say i will leave alone and look for another plumber, although that wont be easy here, thanks again

 

[Riley]

Yeah unfortunately they work on mains pressure so I'm sure you can imagine the damage potential

 

[joni os]

Reluctance to give detail of recharging expansion vessel is understandable given risk. A video on youtube, purporting to show correct method, fails to clarify an important step. Water cannot be compressed. As this video has had over 1/4 million views, there must be many followers who think, incorrectly, their vessel has correct pressure.

 

[townfanjon]

I could be available on a fix / free holiday of course lol