This combi is now 7 or 8 years old and has given good service, the overflow pipe which is vented external to the house has dripped for some time. Now the drip of water has increased to several litres a day. Has anyone got any ideas.
if filling key is not in place,then cold mains pressure is being fed into heating via plated heat exchanger.drop pressure of combi ,if pressure rises on its own then new domestic hot water plated heat exchanger is requred
billy
September 2009
you need your expansion vessel re-pressurised and the pressure relief valve replaced. check that the filling loop is properly closed.