Britony Combi chaffoteaux & Maury system . Hot water tap system keeps losing pressure! Radiator system fine but water pressure on hot water tap system keeps dropping to below 1 Bar so that we get hunting clanging banging noises from pipes.... if i top up system from mains feed it goes quiet again but then will suddenly drop without any visible leaks !!! driving me nuts any ideas please

Doug C, April 2010

It could be the pressure relief valve that is passing a small quantity of water. The outlet of this valve should be piped through the wall of your house. Find the end of the outlet pipe & see if it seems wet or is actually dripping. I checked mine by attaching a plasic bag for a couple of days (it filled with about half a cup of water in that time). If it is passing, you need to replace it. The problem I've had is that it was replaced about three months ago - everything was OK but has started leaking again & am not sure what is causing this.

Hope this helps.

Brian Ninness, September 2010