It's worth knowing how S plan works, and realising that it essentially puts the timer-stat-valve all in series and its actually the valve, which when it has fully opened, hits a limit switch which turns the boiler and pump on.
Once you learn that - the rest is quite simple.
Indeed, took me a little white of poring over Antmans diagrams (he's modified his original for me a couple of times) to realise this
Perhaps it might be better to move these heating controller posts out of this thread and into somewhere more appropriate?
Yeah sorry about the hijacking
