Only one radiator - upstairs- is heating up, I have drained all the air s far as i can see,I have tried isolating each rad but no success, I drained one rad and it started to heat but when i closed the valve again it cooleddown andwillnot heat up.

andy, June 2007

what type of system have you ?
is it the closest rad to the pump thats getting warm ?

need more info

hi-spec plumbing, June 2007