Drayton MA1 mid position actuator intermittent fault.

[Tomcat]

Can anyone advise what could be the cause and how to overcome an actuator intermittently not responding when boiler is calling for heat.
Possibly slightly loose fitting to valve, as actuator re-activates with hand pressure movement when boiler is calling for heat. This is an intermittent fault and is more likely to happen when hot, suggesting an expansion influence.

 

[Deleted member 120897]

If it moves upon persuasion, I would have thought a sticking motor.

 

[Tomcat]

If it moves upon persuasion, I would have thought a sticking motor.

Thanks for your reply sir.
In addition to my post I should have said that I have in the past unclipped the actuator for any obvious cause, but there was nothing that my untrained eye could see.
The unit is about 5 years old and the fault started about 3 years ago. Finding the cause was a matter of elimination when I could not see a fault code on the boiler.
Maybe if I opened the actuator and applied some WD40 it might free the sticking motor if your suggestion is correct ?

 

[Deleted member 120897]

You could, but it could also be gears slipping, which would mean a new actuator head.