In an earlier contribution to this discussion,
Andy Hall wrote:

On Fri, 2 Jan 2004 16:54:01 -0000, "Set Square"
wrote:



In your case, there is no room stat at present, so the CH demand
from the programmer goes straight to the zone valve motor. You need
to intercept this wire, and connect the switching end of your room
stat in series with it. You should be able to do this all within the
airing cupboard - provided this will give you adequate radio contact
with the programmable/display end of the stat.

It would be better to take the timing function for the CH from the
existing programmer out of the occasion completely because this type
of room controller has timing functions with setback, optimisation
etc. wihich will do a better job. I suppose there's nothing wrong
with leaving it in place but setting the existing controller to 24hr
mode to provide a permanent live.......


Taking it from the programmer (and, indeed, leaving CH on constant) has the
advantage that the CH can easily be turned off from a central point
(particularly if he subsequently adds more zones) without affecting the HW
and without needing to change any settings on the progammable stat.

If he *does* provide the programmable stat with a permanent live, it's
important that he takes it from a point *after* the isolation switch for the
whole system.
--
Cheers,
Set Square
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