Help Radiator Valve!!!

[BRUNOBEN]

Hi All. Can anyone please help me. I have been decorating and had to take the radiator off the wall, but on putting it back on I am having diffilculty in stopping it leaking from the side where the numbers are. I came across a valve which looks like a reducer of some sort but it does`nt seem to fit Tried fitting it both ways but unable to sort out which way it goes, and nut does`nt fit the thread. Any help is very much appreciated(carpet soaking). Many thanks in anticipation. Paul.

 

[Mike Jackson]

If you've only taken it off to decorate why do you need this other valve? Have you altered something as well?

 

[GroundControl]

think we may need a photo to understand your question