Drayton MA1 won’t select M or W once H has been selected

[G0009348]

Hello, I have just replaced my Drayton MA1 actuator as the boiler would not switch off. All worked as expected for 3 weeks but now, whenever the heating comes on and the black tab moves to H, it never moves to W or mid position unless I turn the mains off and the actuator seems to release from the H position.
I’ve tried resetting the programmer and turning the thermostat down to its lowest to try turn the heating off put no joy.

Is there any other tests I can do to see if it’s a wiring issue or a switch issue?

I’ve tested the value and it can be moved by hand so belive the issue is in the actuator, which is only 3 weeks old or it’s wiring.

Any guidance appreciated

 

[G0009348]

Just removed the actuator head whilst stuck in H position, manually turned the valve to what would be the W and the boiler turned off, so my assumption is that the motor holding the valve open is not getting a signal to close.

Any help on when to go from here?

 

[CBW]

Remove the cover on the head and check for loose screws, I’ve had this on a lot of Drayton 2 ports recently.