Morning,
I have a conventional CH system with room and hot water thermostats and a Drayton Mid Position valve, which I recall replacing a good few years ago. The boiler is not firing when there is demand from the room stat but it does when there is demand from the water stat. I think the circuit board in the MPV is faulty, possibly what appears to be a relay. The synchron motor works and the water valve operates. Grateful for any thoughts.
TVMIA