Very strange Zone valve problem

[suffolkspark]

if you remove it from the valve and try to run it does it freely open all the way? if it does and the valve feels nice and free its got to be an alignment issue

 

[markythesparky]

So, been back today and the new valve was stuck in a position that wouldn’t trigger the micro switch. I moved the manual lever and suddenly the motor then moved the mechanism to the right position and the boiler fired.

When the stat was turned down the mechanism didn’t return as far as the old valve did.

Thoughts would be very welcome please.

 

[suffolkspark]

Did you try the head removed from the valve?

 

[Devonchris]

This sounds like the operation of a 3 port valve. I think we are all assuming it's a 2 port valve. Can you confirm.

If it is 3 port then you need power to the white and grey to move the valve all the way and trigger the orange CFH to the boiler. If you only have power to white then the valve will only move to the centre position.

Could be that the wiring was altered when the new boiler was fitted and its been like this since then?

 

[markythesparky]

Yes it’s a 2 port valve. Sorry, I should have said that at the start.

My client is refusing to believe it’s a sticky mechanics as this is the third he’s had.