multi-zone central heating

["David Amphlett" <dave_yahoo@xxxxxxxxxxxx>]

Anyone used something like this motorised valve: http://www.danfoss-
randall.co.uk/Site/downloads/226.PDF to control the water flow
through each radiator individually?

I'd like a thermostat in each room, and one of these for each
radiator. I could then have the boiler switch on if ANY thermostat is
triggered, and only have the valves open on the radiators in the
rooms where the thermostats were triggered. (in otherwords, 1 zone
per room).

One thing I'm not clear on is whether I'd want to plumb these in
under the floorboards or not - they seem to have a little metal
slider which I assume is a manual switchover, which makes me think
they should be visible.

I think X10 is a reasonable control strategy for this sort of thing,
and so assume I need a AW12 for each valve, but do AW12's respond to
status requests to say whether they are currently on or off? (it
seems like such a waste to have remote control, but have to do dead
reckoning to figure out if stuff's on or not - status reporting
should be mandatory on all X10 kit!)

Any thoughts / experiences shared appreciated

Dave