Y8610U PID boiler conversion vent damper question

Brant Beach

replaced standing pilot with kit. Works ok except the vent damper does not close after call for heat ends. Vent damper is new. I tried a different wire harness, made no difference. I also had an old vent damper, tried it and it opened on call for heat but did not close when call ended. I have the TH-W wired to the G terminal on the also new Transformer/Relay. Is that the wrong terminal? I thought it was correct according to the diagram. Thanks for any help. BB

Steamhead

You need 24V on the 24V terminal all the time for the damper to close. That's where the power comes from to close it. The thermostat circuit should be fed from the R terminal on the transformer- if so, just run a wire from there to the 24V terminal, and it should work.

Brant Beach

Thank you. I did try that and the damper closed. I do have something else mis wired though. R & C are 24v hot and neutral on the transformer. R goes thru tt to G terminal thru aquastat and spill switch and flame rollout to 24V on 8610. C goes to 24V GND on 8610. TH-W on 8610 should go to R or G? if not, where?
Also i do not have thermostat wired yet, I have been testing by tt wires

Steamhead

R terminal on transformer goes directly to 24V on module, without interruption.

The G terminal on the relay supplies 24 volts to the relay coil. The switched wire coming back from thermostat to G terminal on relay also goes to TH-W. Some relays have an output wire from a relay contact that routes 24 volts out to the TH-W terminal. On others you just splice a piece of wire into the wire going to the G terminal and run that to TH-W.. In both cases, the wire going to TH-W must pass through the high limit control.