the pressure gauge has gone up to 2.7 on the pressure clock and the boiler?

Iagree with Brian, you could do with some who knows what to look for IE gas safe eng.

erj
April 2011

make sure the filling loop is disconnected to start one of the valves could be leaking.

does it over pressurise when its on if yes its possibly a faulty pressure vessel.

I havnt looked but if its a combi boiler it could be a hole in the plate heat exchanger.

Brian Emian Plumbing & Heating
April 2011