In message , Tim
Streater writes
In article o.uk,
"Dave Liquorice" wrote:

On Fri, 17 Jun 2011 21:07:28 +0100, Tim Streater wrote:

I assume that these things control the rads directly, i.e. they
turn the TRV on/off as they think the need arises?
Er, no not in the context of this thread so far that is. I think you
can get things that do do what you suggest.
This thread is about a normal programmable thermostat. Generally
they
are just a replacement for the traditional bimetal mechanical
thermostat.
What they offer is a temperature profile through the day. For
example
at night it will have a set point of say 15C, then in the morning it
could have 19C for a couple of hours then drop back to 15C when
everyone is at work through the day, back up to 18 when the kids come
home and 21C for slobing out infront of the telly after dinner.

So is each of these just working by turning the boiler on/off then? If
they're not controlling the TRVs, and a thermostat wants to say "That's
enough heat in this room thanks", what if another wants the boiler on?
Or are they separate heating circuits each with its own shutoff valve
and separate pipework?


There would normally be just one, it's just a replacement for a single
temp room stat. Though they can be used to control zone valves etc. if
you want, but that isn't waht is being talked about here
--
Chris French