Central Heating control valve problem

[morphboy]

With my central Heating on I find that the danfoss HSA3 valve will not go right over I have programmer danfoss cp715.
Below are voltages I find with CH(central heating radiators) and HW(hot water tank)

With CH and stat only on for heating then grey 240v,orange 0v, blue 0v,brown/white 240. Valve goes to mid position and nothing happens.
If I move valve to far side pump comes on and radiators are warming then grey 240v,orange 240v, blue 0v, brown/white 240v.

With HW on only and heating then grey 25v, orange 240v, blue 0v, brown/white 0v.

If HW on and heating then I add CH heating valve goes to mid position then grey 25v, orange 240v, blue 0v, brown/white 240v.

Any suggestions please?

[Whiter]

Try a new valve head.

[morphboy]

I tried the actuator off the valve head and it worked ok, I found the mechanical/water diverter tight in places, I moved it backwards and forwards a number of times and everything works ok now , but as you suggest I will need to get another valve as it will probably tighten up again but it will be ok until I do.
Many thanks for the reply
Morphboy