11-29-2023 11:27 AM
hopefully easy question. Have older hot water boiler with a single thermostat wire (white and black). Previous thermostat required C wire so ran external C wire adapter (single wire, white, red). Now want to use Nest Learning 3 thermostat. Apparently after trying with just the boiler wire, it does not want to charge the battery sufficiently, so want to hook up previously used external C wire. What is correct placement of boiler wires (white, black) and C wire (white, red). I assume boiler white goes to W1, boiler black to Rh, C white to C, but not sure where C red should go. Or if I have everything incorrect??? thanks for help
12-06-2023 06:02 AM
Hello IWM3,
Thank you for reaching out with your inquiry regarding the wiring of your Nest Learning Thermostat in connection with an older hot water boiler system. We appreciate your detailed description of the existing wiring setup and your attempt to integrate the Nest Thermostat into the system.
It seems you are on the right track with your assumptions. To clarify and guide you through the wiring process, please follow the suggested connections below:
Keep in mind that the Nest Learning Thermostat is designed to be compatible with a wide range of heating and cooling systems. However, variations in wiring setups may exist, and it's crucial to refer to the Nest Thermostat installation guide.
If you encounter any challenges or have further questions, let me know.
Regards,
Mark