I have a problem with noises in the central heating pipes. We have a Worcester Bosch 30CDi Conventional boiler, radiators are mostly new, but replaced at different times. All but 2 radiators have thermostats fitted.
The problem happens when the heating has been on for a while and, I think probably when all the controlled radiators are up to temperature. Then a kind of howling noise sets up and I can feel all the pipes close to the boiler vibrating. Usually if I turn up one of the thermostats the noise goes away for a while, but then comes back. I've checked that the two open radiators are actually open and I've bled the upstairs radiators several times. Bleeding did seem to help in the past, but has less effect now.
Any ideas?
The problem happens when the heating has been on for a while and, I think probably when all the controlled radiators are up to temperature. Then a kind of howling noise sets up and I can feel all the pipes close to the boiler vibrating. Usually if I turn up one of the thermostats the noise goes away for a while, but then comes back. I've checked that the two open radiators are actually open and I've bled the upstairs radiators several times. Bleeding did seem to help in the past, but has less effect now.
Any ideas?
