Another option if the plumbing is appropriate could be to fit a zone
valve with a timer/thermostat for the areas not wanted during the day.
You could then use a setback thermostat to just drop the temperature a
little.



I wanted to do this and asked Honeywell for advice, as I have a Honeywell
CM67 ChronoTherm (fancy thermostat). A very nice man at Honeywell sent me a
wiring diagram for three zones and hot water, I actually wanted 4 zones and
no HW control but it is easy to see how it is all wired up.

Cheers
Jonathan