Hi I have a problem with noisy TRVs.
I Have a Baxi combi boiler supplying 6 radiators with Caleffi thermostatic valves and a towel rail with plain locksheild vales (fully open flow and return). When any of the radiators reach the point where the are satisfied for heat the valves make a loud noisy that changes in pitch till it stops this can take 10 minuets. It sounds like a hammer drill and is loud enough for my neighbours to ask about it. Not good in a morning as you have to get up when the heating comes on or get up to a cold house.
Some one told me I need to have a Differential Bypass Valve fitted; what does this do and why don't these need to be fitted to all heating systems?
Cheers Norman