TRV

[browneye23]

I changed a TRV on one of radiators two weeks ago as the old was broken.
(I tried to release with a screwdriver and also removed the whole pin but the hot water still wasn’t being released through)

The pipe around the valve was very hot so it was clearly this.

I then replaced the old TRV with a new one and everything was working perfectly fine for two weeks.
I had turned the setting down to 2 in warmer climes but at the weekend I put it back up to 5 to let a bit more heat through.
For some reason the new valve has stopped working just in the same way as the old one!!
The pipe around the TVR nice and warm but nothing getting through and warming up the radiator!
Again I have tried to release the pin but still nothing.

My question is – am I really unlucky that and it’s a big coincidence or is there a fundamentally bigger problem?

I have learned maybe it’s just best to leave them all open on full from now one so they don’t stick!!

 

[warmadmax]

WD40 to clear up sticky pins,

the pin should move up and down, returning to fully up naturally,
the TRV head presses down on the pin when it reaches the set temp.

did you check your water? it could be sludge gumming up the valve,
in which case you want to look at flushing it clean and filling back up with an inhibitor.

 

[browneye23]

All other radiators are working fine.
When I drained the system there was no sludge coming from the outlets everything was clear.

This TRV is a different make to my others it moves freely up and down with a screwdriver head.
Even a tip a British Gas engineer showed me by gently tapping it with a hammer hasn’t worked.

Will give it a spray of WD40 to see if this helps.

 

[warmadmax]

Only other thing that springs to mind, is it a bi-directional flow TRV? (should be but check!)

if it's not, and it's on the wrong side (flow instead of return) then it will be forced shut by the incoming water and stay closed.