01-17-2024 02:35 PM
After replacing my 4-wire thermostat (R, G, Y, W with Rh & Rc jumped) all of the initial tests fail. Neither fan nor heat will start. No errors are indicated. I checked the new gas furnace system board and there is a 5th blue wire connected which I believe is common. There is a blue wire in the wall behind the old thermostat. I'm thinking next step is to complete that connection to see if that will do the trick. But I don't want to fry anything. Anyone out there who may know if this is a bad idea?
Thanks.
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02-03-2024 01:17 PM
Hello POPTOPP,
It sounds like you're going through a bit of a challenge with your Nest Thermostat installation.
Connecting the blue wire to the common (C) terminal on the new thermostat should generally be a safe and logical next step. The common wire is often necessary for providing continuous power to the thermostat. Before making any changes, though, it's a good idea to turn off the power to your heating system to avoid any potential issues. Once that's done, connecting the blue wire from the wall to the C terminal on the thermostat and the furnace system board should help provide a common ground.
If you're unsure or uncomfortable with the process, it might be a good idea to reach out to a professional HVAC technician to assist you. They can ensure the proper installation and help troubleshoot any issues.
I hope your Nest thermostat gets up and runs smoothly soon. Let us know if you need more help.
Best regards,
Mark
02-03-2024 01:17 PM
Hello POPTOPP,
It sounds like you're going through a bit of a challenge with your Nest Thermostat installation.
Connecting the blue wire to the common (C) terminal on the new thermostat should generally be a safe and logical next step. The common wire is often necessary for providing continuous power to the thermostat. Before making any changes, though, it's a good idea to turn off the power to your heating system to avoid any potential issues. Once that's done, connecting the blue wire from the wall to the C terminal on the thermostat and the furnace system board should help provide a common ground.
If you're unsure or uncomfortable with the process, it might be a good idea to reach out to a professional HVAC technician to assist you. They can ensure the proper installation and help troubleshoot any issues.
I hope your Nest thermostat gets up and runs smoothly soon. Let us know if you need more help.
Best regards,
Mark
03-03-2024 10:36 AM
Thanks for your confirmation. This did solve the issue.
03-03-2024 11:45 PM
Hey POPTOPP,
Thanks for the update! We're glad to hear that the issue is now resolved. Please feel free to create a new thread if you have any questions or concerns, as we'll be willing to help.
I appreciate your input, Mark.
Cheers,
Jenelyn