how to wire a thermosat?

thanks Ian, there is not much of a wiring centre, all the cables come to the back of the landis controller, the pump cable, boiler feed etc, i plan to put the stat near this as i can put the cable in easily as there is a void there, i can pick up a supply easy and the pump wire is on terminal 4 of the controller, is that the wire that has to go to the stat?
Dek