DIY Doctor UK DIY Forums

I've got an old house and the trv radiator valve heads are ancient, at least 25 years They are M28 size. I've got them all off and the push pins underneath in the radiator valves are all working. But the new M28 valves heads are hard to screw on. They sit too shallow and it's difficult getting the round nut to bite and turn on the thread on the radiator to hold them in place...I've got 3 out of 4 on just secured with a 1/4 turn. The other just keeps popping off. I could file a few mm from the plastic feet to allow the trv to sit more flush, and allow the nut to bite better. Thought I'd better ask before doing this. Thanks++

Hi sorekneerunrun,
There is a fair chance that the threads are not compatible, you should be able to get 3 or 4 complete turns on the valve nut. If you are not getting this the head will not be seating properly and will not work correctly. Best to fit the valves that were supplied with the heads.
Regards S

When I got my electronic heads, they came with a kit of adaptors, for RA, RAV, RAVL I used eQ-3 as at that time the cheapest, and latter used TP-Link (Kasa) which also included a kit.