installing old TRVs to new rad.s

[SimoninEaston]

I think I'm being a bit slow here, but...
I'm replacing 2 rad.s, I have bought one new valve for each new rad., which come with suitable tails that fit into the rad.s. I am going to put my 2 existing Honeywell TRVs back on and I notice that both the in side and the out side are 15mm compression - how do I join the the TRVs to the new rad.s?

 

[kbdiy]

Use the tails from the old rads as they are matched to your existing valves. Simples.

 

[SimoninEaston]

I can see why you suggested that solution but the old tails didn't work. I know that sounds a bit odd, but bear with me. The thread sizes were OK but they wouldn't tighten up properly - they had a drain point and when the drain point was aligned properly i.e. pointing down, the other components were loose. I tried using PTFE tape and plumbers putty to stop the leaks but to no avail. The only time all the components were tight, the drain point was pointing skywards... !
I've seen a nice product available from Screwfix:
http://www.screwfix.com/p/radiator-compression-valve-tail-15mm-pack-of-2/10954
I think they'll do the trick!

 

[kbdiy]

Packing the old tails with PTFE would allow you to position the drain-offs correctly, it just takes a few extra turns and care when tightening.

 

[polesapart]

http://www.screwfix.com/p/loctite-55-pipe-seal-cord-50m/42142