Hi,
I hope someone can help me with this please.
I recently had two new radiators installed and at first everything was fine. Now, two radiators (one of which was one of the new ones) makes a high pitch whining noise (although not all the time). I have bleed the radiators but they were all fine. The new radiator that whines has a thermostatic valve but the other radiator that whines is a lot older and does not. The two radiators are in adjacent rooms upstairs.
Thanks for your help
Regards
Nick