Central heating not working 3 port valve?

[Kay101]

Hi all,


Not posted for some time but come up against a small problem.
Been off the tools for many years now but I think I know the issue but looking for some reassurance
Boiler isn't firing when programmer and room stat is calling for heating, but does for HW.
It's a Y plan system, new house and only just noticed so not fully inspected.

From memory if the motor isn't working it won't turn to CH and send a signal out on orange to fire the boiler, am I right?
I don't know the type of valve, will check tomorrow but I guess it hopefully just a case of fitting a new motor?

 

[Aquarius]

Unless the microswitch Isn’t making, motor could be fine and microswitch faulty. Should get 240/230vac on the orange if making on switch. Could even be room stat, though unlikely.

 

[Darren Jackson]

Most likely the 3-port, but make sure there's a feed from wall stat to 3-port before you commit.