i have a ravenheat combi he85t i have got problems with it the pressure drops down to o and i got to keep topping it up and when the boiler first goes on the boiler starts banging i have got to run the hot water to stop the banging have you got any answers to this problem

carol griffiths, April 2008

Presure drop if not absolutly visible could be safety relief valve leaking to out side check outside pipe when you top up. Banging is caused by air in pump and water jacket automatic air vent is on top of pump it looks like a dust cap off a car tyre take off cap and air will automaticaly vent until little pot fills up

Danny, April 2008

Banging is due to air traped in the heat exchanger (when u refill the system) or a lack of water volume passing through your sytem with air in it....assume it's gurgling at rad and stuff too...

System needs to be refilled to 1 - 1.5 bar, if pressure is continually dropping you may have a leak, or a faulty safety release valve (or a stuck one / dirty one) but either way, firstly the cause of the pressure drop has to be established..

T, April 2008