Motorised Actuator turning on by itself

[MikeyTang]

Hi All,

I have a Myson MPE222 which intermittently comes on by itself for a about a minute then turns itself off. This happens randomly thoughout the day and thermostat is not calling for heat when it happens. I had a look at the wiring and the actuator seems to be wired properly. One thing I did notice was the brown wire is connected to a terminal with 2 other wires. One wire is connected to the thermostat, the other wire is a switch live which I dont know what its connected to.

Can this switch live be the issue? Or any other ideas why it might be turning itself on?

Thanks in advance.

 

[Harry Bloomfield]

Can this switch live be the issue? Or any other ideas why it might be turning itself on?

Might you have a frost stat somewhere, which is seeing a low enough temperature so as to trigger a need for some heat?

 

[MikeyTang]

Might you have a frost stat somewhere, which is seeing a low enough temperature so as to trigger a need for some heat?

Thanks for the reply. Does the frost stat only activate one valve, as it only the downstairs heating that comes on.

 

[Harry Bloomfield]

Thanks for the reply. Does the frost stat only activate one valve, as it only the downstairs heating that comes on.

That depends on how it was wired..

 

[MikeyTang]

That depends on how it was wired..

Thanks again for the reply. It give me another avenue to venture down in seeing if the actuator is faulty

 

[MikeyTang]

There’s a Honeywell frost stat on the wall next to the boiler. Took the cover off and found the dial was positioned with the 5 and arrow pointing in the 9 o clock direction. Am I right this should be pointing to 12 o clock to set it to 5 degrees?

 

[jackthom]

Yes I’m pretty sure the 5 degree arrow should be at the 12 O’clock position. Otherwise it will switch on the boiler at a much higher temperature.

 

[MikeyTang]

Yes I’m pretty sure the 5 degree arrow should be at the 12 O’clock position. Otherwise it will switch on the boiler at a much higher temperature.

That’s what I was thinking aswell. Have moved the 5 to the 12 o clock position which will hopefully stop my heating from coming in randomly.