Synchron motor....

[HayZee518]

synchron

sybchron is just a name. not to be confused with a synchronous motor - which is a different animal in itself.

could you send me the wiring diagram?

[HayZee518]

zone valve

the motor is held to the gearbox by one screw and a tab. loosen the screw and remove and rotate the motor away from the tab. you can now remove the motor.
if your valve has two microswitches, you'll have a common and two returns plus two more for the motor which operates on 24vac.
one microswitch you'll have one pair [gray and orange] and two motor leads.
one lead is spliced into the motor pair so the motor shuts off when the valve is open.
closing the valve its spring loaded to fail safe close.
with power off and the boiler off, move the lever open and release. if the gearbox is ok, it should go back to close.
if it don't you have a gearbox problem.
replace the gearbox head.
old valve you remove four screws and whole head comes off. [CAUTION YOU WILL DRAIN YOUR SYSTEM THROUGH THIS VALVE] shut off the inflow and outflow to this valve.
new style of valve, loosen two opposing screws and the upper part of the gearbox will come off but the valve guts will stay there.

[mrcaptainbob]

It was miserable last winter. The darned zone had a real issue heating up unless I put the motor to manual over ride. Was dinkin' around with looking at the wiring setup and found nothing. My wife complained that she could not change the t'stat features due to a padlock icon showing. I used the reset to factory settings button on the inside back and the icon finally disappeared. Still no luck. Very difficult to manage settings on the t'stat. New batteries did not help. So....I removed it and twisted the 'stat wires together. HEAT!! Replaced the old t'stat and all now all is well. Who knew a digital t'stat goes bad after ten years??!!