Roger Mills wrote:
In an earlier contribution to this discussion,
The Natural Philosopher wrote:

If I had my time again I'd zone every single room. With a motorised
valve, and run a ****load of cables back to the timer and pumps etc.

We have a lot of rooms we don't use all the time, and it would be far
more economical to simply flick a switch and have them go to 'frost
stat' settings when not in use.

It would certainly be nice to have an S++++ system, with a programmable stat
in every room - so as to be able to heat each room only when needed. You
could probably do it without too much plumbing by using (don't know the
correct description) things like TRVs with little heaters in them to turn
individual rads on and off by remote control. Would need a lot of wiring
though, and I don't know whether these things have secondary contacts which
close when the valve is open - like a proper 2-port zone valve.

Such a system would be a nightmare to programme though unless your room
usage followed a very regular pattern. Even then, you'd have to tell each
individual stat about things like going on holiday for X days. Really needs
to be programmable from a single point - with the ability to apply global
settings to all stats in one go - but I'm not sure how to go about that. I
don't really want to run a dedicated PC *just* the operate the heating!

No need to program anything. Just go into a room, switch it ON, forget
timers by and large, and if its too cold on comes the heating.

You just 'wire OR' the motorised valves..(connect em in parallel)