lost pressure in glowworm 30ci

[pressur1sed]

I have a glowworm 30ci. For a little while (several months) it has been loosing pressure, primarily when off but sometimes when running. I have had a plumber out and he pumped up the expansion vessel, which worked for half a day. At the time it was dumping water whenever on, and this continued until recently. The dumping of water has now ceased and I am still losing pressure. Also the pressure can not be resumed by simply opening the valve. The only way is to pump up the expansion vessel. This has worked until today. There appears to be air pressure in the vessel but this is no longer giving me the green light. I can not see any evidence of water or air leaks. Has anyone got any idea's please

 

[weareleeds]

There is only a certain amount of air you can put in exp vessel which should be at around 1 bar.The reason you cant put in water is that the filling tap will have failed (very common) so you will either need to change filling valve or put in a remote filling loop between mains cold water & htg pipe under boiler somewhere. Once filled with water to around 1 bar it should work but before switching on go round system & check for water leaks especially under plastic rad valve tops on glands

 

[superdupergasman]

is the schreader valve of the expansion vessle leaking the air you are pumping in???

Is the PRV passing now that it has been over used???

As said the filling loop will have siezed or over tightened and therefor broken off.

I would, if I were you, get a professional out, glowworm or BG, to check the boiler over and repair the faults.... you have been tampering with something you dont know much about....its a time bomb waiting to explode if your not careful....GET IT CHECKED rather than fiddling..... a little knowledge is dangerous!