I have in the past installed Drayton TRV4s on a number of radiators on the 1st floor of my house, which has a suspended chipboard floor. My previous TRVs (not Drayton) had bodies which screwed into the bottom of the radiator using a large allen key, whereas the TRV4 has external flats onto which an adjustable spanner can be used. This meant that the TRV4 body is longer than that on my previous TRVs, resulting in the two copper water supply and return pipes having to be moved apart to some extent before connection. This didn't present a problem upstairs, since there is a considerable amount of lateral movement on these pipes under the floor boarding.
However, we have concrete floor downstairs and I am facing the same problem but in different circumstances. Of course the copper supply pipes have very little movement in the concrete and I'm finding with the Drayton TRV4 that the distance between the centre lines of the TRV4 and the lockshield valve at the other end of the radiator is greater than the distance between the centre lines of the two supply pipes!
The copper supply pipes only protrude from the concrete some 6 - 8 inches, so have little or no flexibility in them. I could insert a pair of soldered obtuse elbows into the pipe to offset it, but the offset may then be too large.
Must I face the fact that I cannot use the Drayton TRV4 under these circumstances and look for an alternative that has the allen key body fitting?