hi.

i have a problem with my boiler. when i open that filling loop, it fills the boiler but the pressure goes up to 3 bars ! and it starts humming and making noises so i presume it starts draining to excess water. but when i close the loop - pressure goes down to zero and i have no central heating then. any ideas on that ? thanks

Thomas, November 2009

could also need the expansion vessel topping up with air

123, November 2009

you have an auto over presser valve (red nob right side) it can be manuley opened it may be stuck open

gas man, November 2009

water is leaking. check pressure discharge pipe if leaking than replace pressure valve in the boiler
it not than is is leaking elsewhare

m, November 2009