In message , Mike Barnard
writes

The dilemma is whether to zone off the rear two rooms upstairs.

I cannot answer this from a DIY perspective, because I didn't do ours,
but, having had it done, I think it is wonderful. We have four entirely
independent timers, controlling the heating for three areas, plus hot
water, all powered by a conventional oil fired boiler. Different parts
of the house are heated at different times, to suit our needs. The
times can be overridden, of course. Different times for each day of the
week, if required. Yes, there are TRVs on the rads, which help, and in
theory we could run around adjusting them, but who does?

The only downside is reminding the family that hot air rises - it is
fairly pointless having just the downstairs heating on, with all the
bedroom doors wide open :-)

--
Graeme