I just moved into my new flat a few months ago and noticed the pressure guage keeps falling to 0 on my halstead ace high combi boiler when not in use but when heating comes on or i use hot water the guage goes up to 1.5. Should it always drop to 0 when not being used or is it supposed to stay showing around 1

frustrated diy man, May 2010

check for water leaks on radiators and look outside to see if water is going out of discharge pipework before changing expansion vessels etc, usually on the vessel there is a pressure point for a car footpum, the pressure should read approx 0.75 bar, when the system has no pressure on it u can recharge the pressure with the foot pump

higgs, May 2010

either the expansion vessel needs re-pressurising or there is a blockage to the vessel or the vessel needs replacing if you are familiar with combi boilers it's easy to work out which one it is otherwise it needs a long complicated explaination if you know what and where the expansion vessel it would make things a lot easier

brian, May 2010