replacing room thermostat

[JohnW2]

We haven't been told the hw channel us faulty. And I can't see how it could be broken.

Nor can I - unless (as it not impossible) there is a set of contacts which is common to CH and HW.

Bypassing the ch channel is fairly typical when fitting programmable stats to avoid the confusion.

I'm sure it is - but, again, I would regard that as only a stop-gap measure. If there were a programmable stat, I think I would ultimately want a '1-channel' programmer (maybe just a timeswitch) for the HW, to 'avoid the confusion' (and tidy things up) even more convincingly!

Of course, all of this may 'depend' on exactly on how the CH & HW system is configured and wired - there are some odd arrangements around

Kind Regards, John