Wiring the Wyze Thermostat

I am trying to wire in my c-wire adapter but the control board doesn’t have a yellow connection (see photos). Is there a way to wire this?

This is the wiring diagram.

Find the area where the thermostat wires are wire-nutted to the system wires and take a picture of that.

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Ok, When I get home from work today I will do that. Thank you.

Hope these help.


Where does the blue wire go at the furnace, and is it in your wall behind your current thermostat?


Blue wire is unused it looks like

Good. With the power off, take the blue wire and strip a bit more insulation off of it and add it to the thick grey/ thin yellow & green wirenut here

Then take the other end of the blue wire at your thermostat, and connect it to C on your wyze. Tell the wyze app that your “old thermostat” has a C wire during setup, and you don’t need the C wire adapter after all.


Excellent. I’ll give it a shot. Thank you so much!! I’ll be going out of town for a few days but will post the results when I get back. Thanks again!

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Ok so I finally got around to installing the wyze thermostat. After I hooked up all the wires as you had said I was getting nothing on the screen I took out the red wire which I had put into the spot labeled RH and put it into the spot labeled RC and I turned on the system and now I had the wyze symbol on the screen of the thermostat. During the setup in the Wyze app though it told me that there was an extra wire that I needed to disconnect, which was the green wire. Is the green wire not needed or is something else incorrect?

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Did you tell it that your “old thermostat” has a C wire? If not, it would try to have you install the C adapter, which you do not want to do.

You should tell it that your “old thermostat” uses the following wires: Rc, C, Y, G, W.


Well, I thought I did, I’ll restart the setup and make sure. Be right back with the results

Usually if it says you have an “extra wire” it means you forgot to select that wire as existing on the old thermostat, or it thinks you have a C adapter installed.


Well it seems to have made it past the error, now wants to know what fuel W1 uses. I have a gas heater, is that what the W1 is controlling?

W is heat, Y is the air conditioner, and G is the fan.