New CH pump fitted a month ago by a registered plumber. Since then the Central heating and water runs continuously. The Programmer and the Thermostat make no difference to the operation ( they can be OFF and turned right down respectively ) and the boiler is still alight and the pump runs continuosly 24 hours.
So rads are HOT and hot water is HOT. Had a quick look at the jumble of electrical wires where everything meets, including the new CH Pump, and its spaghetti.
My feeling is that in wiring the pump the plumber ( Ha! ) has incorrectly connected it and or disturbed wires. This means that the pump and boiler operation is always powered and not controlled by the Programmer.
Any ideas please.

Mike Groom, December 2009

microswitch on motorised valve is stuck on causing constant demand regardless of what controls are set to, very common fault.

Ian, December 2009