hi can any one help me please. I have above boiler. Recently it let the water out the central heating circuit via the pressure relief valve. I charged the system again and literally watched it fall before my eyes. Went outside and the water had again let by this valve. After charging and turning the valve a couple of times i got the pressure to hold. Now 2 days later the boiler has shut off and drained down again via the pressure relief valve. This time when i charged it their was water bubbling out directly under the nipple. I checked and their is no seem. Can it be patched or does it need replacing? Also should pressure relief valve be changed at same time? Any help much appreciated.

Geoff, November 2008

you shouldnt be able to access water in expansion vessel matey. expansion vessel half air half water, you can charge the air side, water in the air side...split diaphragm in vessel. vessel with no air side (full of water) no room for heating circuit to expand when heated causing pressure to rise 3 bar plus and dump outside.

iain, November 2008

sorry meant to say that the water bubbling under the nipple on the expansion vessel.

Geoff, November 2008