the motor on top of the divertor valve seems to switch to central heating without being switched on. the radiators get red hot then at some point it switches off. still moves the valve to supply hot water on demand at tap but as soon as you switch the tap off it goes back to hot water to the rads even though the heating is not switched on. i have taken the motor off the 3 way valve and you can move it up and down very easily because i though that was the prob but dont think so. i changed the 3 way valve last year and the motor on top of it.
