"Set Square" wrote in message ...
In an earlier contribution to this discussion,
Neil Jones wrote:

"Set Square" wrote in message
...



Whilst this is true, using a conventional programmer with its CH
output connected to the programmable room stats has the advantage
that the heating can be turned off from a single point (e.g. for the
summer) without having to re-programme the stats.

I installed a Honeywell CM67NG RF recently. It has an 'off' setting on
the programmable thermostat part - which is not really off but a
user-selectable frost-free setting which is 5 deg C out of the box,
IIRC.

Neil

Sure - but the earlier discussion related to a system with 2 or more heating
zones, each controlled by a programmable stat. So you would have to turn
each of these off rather than doing it in just one place. Also, I'm not sure
that with some programmable stats you can effectively turn it permanently
off with disturbing the other settings. Maybe you can?


You can, because the programmable stat part is battery powered,
whereas the receiver/controller part is wired into the boiler control
system. If you power of the boiler it removes power from the
receiver/controller (which actually decides to turn the boiler on/off)
but the thermostat itself is still on.