I recently repaired a leak on a rad valve, where some of the system was drained. The system is 0.7 bar cold and when fully operational it goes in the red, could there still be air in the system causing this. It's a combi boiler, glow worm, about 7 years old. Could you please advise me. Many thanks

JJ, January 2013

also check u havent left any boiler valves closed

kash, January 2013

expanssion vessel needs inflating on the boiler. drain down the system, then get a car pump and inflate the tank to 1.5bar. its the red tank fitted to the rear of the boiler it has a car tyre type inflating valve fitted to it it will be on the top or bottom.

kash, January 2013