On Wed, 27 Aug 2003 22:43:32 +0100, "Roger Mills"
wrote:

It all comes down to *exactly* what you want to achieve. In your original
post you said that you wanted to make one radiator come ON and OFF at set
times. This implied that there may be times when you want ONLY this radiator
on without any others being on.

No, I cannot envisage such a situation - except if all the TRVs in the
system had shut off their respective rads - which is possible, but
unlikely to be a problem since they are not likely to remain off for
long - unless the outside temperatuire had warmed up enough to prevent
the main thermostat from switching the boiler on.

However, before doing this, make sure that there are no circumstances where
this radiator is the only path between the boiler flow and return. Depending
on system design, you may need to install a separate by-pass circuit.

I installed the system myself, several years ago. It's a combi-boiler
system. AI am fairly sure there is no need to have any rad permanently
on, serving to keep the cirquit flowing in case all others are turned
off, since I seem to remember the boiler has its own built-in
pressure-operated by-pass, bypassing the whole rad cirquit in that
eventuality.

Thanks also to the other respondees.

Frank