Thermostatic Rad Valves, odd size Tails

[Josephine]

Hi first post here
I want to replace a couple of rad valves with TRVs but as you can see from the pic, the existing tails are bigger than it usual. All the valves I can find have 1/2” bsp Threads both sides, but I either need TRVs with one side to match the tails, or a reduced for the rad.
Any advice please?

 

[ShaunCorbs]

Best not to install a trv on a towel rad as any towels on the rad normally cover it

You won’t get a trv with a 3/4 nut one end

 

[king of pipes]

If you do decide to do it then simply change the radiator tail to 1/2" they come with the trv anyway . Kop

 

[SimonG]

And make sure the towel rail isn't the systems bypass.

 

[Josephine]

Ok thanks!

Towel rail very tall so I don’t think I’m going to hang towels that low, but point taken.

Regarding the towel rail being the bypass, at the moment the towel rail gets so hot that the valve is normally screwed down tight, the other rads work Ok and if it’s a hot day I expect all the other rads with TRVs to be shut anyway. Is that a fair assumption, otherwise what is supposed to happen if all rad valves on a system are shut?