I've bled all the rads twice this week and the pressure is fine at 1.5 but the system makes irritating noises, i.e as if something is tapping the pipes which are all concealed behind my walls. This seems to happen for one minute every five minutes. I can't sleep at night. At the moment I've been switching off at night before bed because the noise is so annoying but so cold I'am in the morning. I hope someone may have a solution the problem.
poor installation this sounds like when your pipes are heating up they're expanding and this needs to be taken into account when installing if insufficient space around pipes they will rub against whatever theyre near usually this occurs under the floor just above thewall if there is a joist there and the pipes have been drilled throught the joist at an angle with a drill bit that is too small