Dave Liquorice wrote:

This is probably a stupid question, but is a room stat worth
bothering with in the first place, when TRVs are in use and
installed ?

Recent building regs say that when nothing is calling for heat the
boiler must be forced off. This is so that it doesn't cycle just
keeping itself hot, thus wasting energy. With a full TRV system you
can probably do this with a flow switch but the pump has o keep
running through a bypass of some sort, then balancing that flow
against a "demand" for heat as a TRV opens may become an issue. Easier
to fit a wireless programable room stat in your main living room and
take the TRV heads off the rads in that room. The TRVs and room stat
will "fight" if you don't.

OK. This is good advice, I will do as you have said - better to do it
right and once, rather than have to go in later and start poking with it
again.