my boiler is only four years old but has the last few weeks had an periodical problem with no hot water.when i check the pressure is low/only half bar?can anyone tell me how to top it up?underneath there is a loop with a screwhead both sides.And if i do this will it solve this problem?i believe the pressure should be between one and two??please help its driving me mad!!!!

Hannie, August 2008

The loop you see has a tap on it from mains pressure. Open the tap until the pressure reaches around 2 bar then close it again. If you go above around 3 bar it will vent off to the outside, so about 2 1/2 bar maximum before you turn it off. You may have a very slight leak somewhere that is losing the pressure. There is usually a rust mark or similar where the leak is.

Trev, August 2008