Problem with installing Drayton MA1 Valve & Actuator?

Hi everyone, I swapped out a failed switchmaster acutuator, and replaced it with a Drayton MA1 and wired it using the original six wire cable from the programmer (Switchmaster SM400 central heating timer control) joined via a junction box to the five cables of the Drayton MA1 as follows:

1. I cut off the lead to the switchmaster. On the switchmaster lead from the wiring cente i connected all the wires to a junction box.
2. I connected the orange and red together. Then joined this to the orange of the new valve.
3. I connected the yellow of the switchmaster lead to the white on the new valve.
4. I connected the white of the switchmaster lead to the grey of the new valve.
5. Finally I connected the blue to blue and earth to earth

However, when I powered everything back up, the valve stays in the Mid position, and doesn't move if I switch over to central heating&water or hot water only.

If i remove the actuator and watch it as i switch between central heating&hotwater and hot water only (on the control unit) the actuator is not moving. The valve itself moves freely by hand.

At first I thought i had a faulty actuator, so I went back to the supplier and they changed it, but the new one does exactly the same thing.


Could you or anyone else advise? I'd be most grateful.