I have a Warmflow Combi oil boiler, c. 8 years old, but not much used. I have drained the cent. heating system down and on re-filling it via the fill hose at the top of the boiler, water started to pour from the side outlet of a small brass pot-shaped vessel connected to pipework also located near the top of the boiler and to the left as viewed from the front. . (It lies behind and near the top of the large red Pressure Vessel on the front of the boiler). Obviously I cannot get operating pressure while this overflow/leak is happening. Is this brass pot a banjaxed pressure overflow and can it be re-set/sealed or must it be replaced? It has a very thin nut/base, and this is how it is connected to the pipework system, presumably. Any advice gratefully received.

douglas, February 2011

THe Device is an Automatic Air vent this has failed probably due to dirt in the system getting under the valve seat there should be a small black plastic screw in the side of the vent which can be screwed closed as a temporary measure but a new AAV will need to be fitted.

www.elanar.co.uk, March 2011