"Christian McArdle" wrote in message
...
It doesn't require a separate zone. That is the best case of course,
but
it
can be taken off the existing rads.

Part L differs, however. A conservatory must have indepedent timing and
heating control for building regulations due to energy efficiency.

They have temp control. When the fan is off little heat floats out to worth
worrying about. Time control? A plug-in timer into the fan heaters socket.
If it brings in the fan heater when the main clock is off then there is no
heat to the fan heater, then the internal temp stat holds off the fan.

For simiplicity's sake, you can probably get away with a zone valve off
the
existing house zone. The problem then is that the conservatory will only
fire up if both it AND the house stat require heat.

Christian.