On Wed, 24 Nov 2004 22:30:02 +0000, a particular chimpanzee named Andy
Hall randomly hit the keyboard and produced:

THe normal arrangement is then for a signal wire from the motorised
valve to go to the boiler switched live. This wire is live if either
thermostat demands and the motorised valve is open accordingly, and
fires up the boiler. Once this live goes away because the
thermostats are satisfied, the boiler is shut off apart from being
able to run the pump to disperse heat.

I think from the behaviour of the boiler when the programmer goes off
there isn't a pump overrun.

You could incorporate a flow switch, but normally the other controls
do the job.

If there wasn't a room thermostat, what would happen then?
--
Hugo Nebula
'What you have to ask yourself is, "if no-one on the internet wants
a piece of this, just how far from the pack have you strayed?"'