Programmer/stat not controlling heating - trying to make sense of wiring?

[Jason90]

Great. I will try this tomorrow and report back. Thanks all for your help today!

 

[Jason90]

Afternoon all.

I was curious as to why this might have started happening and was fiddling with the actuator on the mid position valve this morning. Is it possible this has become "lazy"?

After reseating it on the valve, the voltage I measured as 120 last night is now 80 and the boiler isn't staying on unnecessarily any longer. I have a feeling this isn't a permanent fix though...

 

[D_Hailsham]

How easy is it to turn the valve spindle (about 20 degrees between stops) when the actuator is off? It should not require any force.

If it is stiff, apply some silicon lubricant where the spindle goes through the plate. (WD40 not recommended as it rots the seals)

 

[Jason90]

It's extremely stiff and can only be turned with a wrench. I've found a "silicon oil" spray that I applied about an hour ago and it hasn't improved it.

Sound like the valve needs to be replaced?

 

[jackthom]

Is working it backwards and forwards a number of times plus spraying at intervals making any difference at all? You may get lucky eventually.

 

[Jason90]

Yes. Definitely moving a bit more easily, although still can't move it by hand

 

[Jason90]

Well everything seems to be running ok for now, have tested various combinations of CH and HW on and off. Will keep an eye on it, but at least I know what the issue probably if it recurs. Thanks all for your help!