2

I just purchased an ecobee4 and I found that I need C wire for wifi which is not connected to my current thermostat. However, there 2 extra wires I found in the wall. Could you use one of them for the C wire? Also the board has something already going in to C screw but I think its for something else? It's coming out of the separate brown cable. There is also one wire coming from brown cable going to yellow. I leave these 2 alone?

enter image description here

enter image description here

Improve this question
3
  • 1
    You don't need C for WiFi. You need C for additional power to the thermostat. You need the additional power for... among other things, WiFi.
    – Harper - Reinstate Monica
    Dec 16, 2017 at 0:53
  • Where does the brown cable go? It is powering a doorbell? Or what?
    – Bryce
    Dec 17, 2017 at 5:09
  • @Bryce -- my answer covers that. (it's the cable to the air conditioner compressor)\
    – ThreePhaseEel
    Dec 17, 2017 at 10:53

1 Answer 1

Reset to default
2

Go ahead, hook that blue wire up to C and use it for your Ecobee

As the terminal strip on your furnace control board is typical in that it has room for 2 wires on each screw, you can simply land the blue wire on the furnace control board's C terminal alongside the white wire that's already there.

BTW: the brown cable you're asking about can simply be left alone -- it's the cable that connects your thermostat's yellow wire (Y terminal) and the furnace control board's C terminal to the compressor contactor in your air conditioner so the thermostat can turn it on and off when things get sweltering in the summertime.

Improve this answer
2
  • Thank you, Quick question, the brown cable has 2 wires coming out of, one is Yellow which is also going Y and C which is going C. So I leave the extra yellow as is correct? and just use the blue coming out of the white cable as my C.
    – Sam
    Dec 16, 2017 at 0:40
  • @Sam -- that is correct. the white wire from the brown cable needs to be left as-is as well
    – ThreePhaseEel
    Dec 16, 2017 at 1:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.