My Ariston Micro Combi 23mffi keeps rising up to 2.7 bar. I have drained the system to let it fall back to 1.7 but it climbs back up over about a day or two. It never gets higher than 2.9bar, but I am worried about it bursting a pipe when I put the central heating on. Any ideas of how to remedy this, there doesn't appear to be any way of decreasing the pressure into the boiler from the cold inlet short of turningback the inlet tap.

Nigel Bates, September 2005

either filling loop on or expansion vessel in boiler full of water where it should be half water and half compressed air

gasman2007, September 2007

some problem on my combi boiler...although its a Baxi.
domestic heat exchanger was leaking water into the central heating system. This is the only point where the hot water and heating systems meet. Once fixed, recommend that you treat your c/h with an anti corrosion product if not done already.

approx 60 to replace.

scott, November 2006

should the filling loop be fully closed all the time?....is this the silver flex pipe providing cold water to the boiler??

andrew, March 2006

Filling loop letting by/not fully closed
or (worst case) leak in the secondary heat exchanger

RS Plumbing, November 2005