In article ,
Set Square wrote:
In think that in your position, I would implement my own - using a mains
relay and a pipe stat. Connect the coil of the relay to the boiler
switched live. Connect the relay contacts to a permanent live and to the
pump. Connect the pipe stat contacts in parallel with the relay
contacts. Install the pipe stat on the boiler flow pipe and set it a
similar temperature to the boiler's own stat (a bit of experimentation
may be required!)

This will work, but you might have to add a second relay to the pump, as
you'll be feeding volts to it which may then go somewhere else that they
shouldn't, as it were, with the system 'off'. That's what happened with
mine. I never bothered working out exactly why, but IIRC it caused the
system to fire continuously.

--
*Hard work pays off in the future. Laziness pays off now *

Dave Plowman London SW 12
RIP Acorn