Room Stat wiring help

[leonlikestrees]

Hi all,

Further to my previous post, I've finally gotten my head around the heating system (well, partially anyway!) in my new house.

As the CH is driven from the Thermal Store, turning the CH on or off is simply a case of activating the CH pump.

I've got an old room stat/ programmer, and it has L&N connections, common, demand, and satisified connections.

At the moment, the pump just has a plug, and I need to switch on the plug to make the CH work.
So I presume I just wire the mains to L&N to give the programmer power.

I'm not sure how the power is then delivered to the pump.
Do I connect common and demand to the pump place of my current wall plug, or are they just signalling connections?
If they are signalling connections, does that mean I need something else like a relay to provide power to the pump when switched by the common and demand?

 

[stem]

Something must be switching the pump on / off already, unless it's running 24/7, in which case it will not be a permanent supply. But without seeing it, it is impossible to tell. The plug may be just used as a method of connection to facilitate an easy change of the pump. If so, then it will have a switched supply and not suitable for a programmer.