Wyze Thermostat - Wiring Help!

Hi! I received my thermostat and have read through a bunch of the other threads and have been trying to figure out where I am going wrong. I would love some help!!

What went wrong?

explain what are looking at?

Should find the splice to those whiye wires. someone is not using standard wire.

Sorry my thermo stat will not power on.

The photo is the wiring at the furnace control board and c wire adapter

I can’t tell exactly from the pictures but it may be where you have the G wire connected at your thermostat. I had the same issue with no power at the thermostat until I realized the G wire needs to connect to the C terminal of the thermostat. That wasn’t very clear in the instructions but is a key component of the C adapter.

it appears that someone used two sets of wires on your setup…

the colored wires you see at your adapter/ thermostat should be the same colors on the control board on the furnace. not the white you are currently seeing

more than likely you will have to trace the wires from the furnace, ( assuming you haven’t done so already) to this corresponding color. so follow that G wire from the picture on the left all the way to the point it is spliced into the colored wires… write down what color the G is spliced into and do the same for all of them. then use that cheat sheet to do the connections to the adapter. if that G wire actually connects to the yellow cable you would have to not follow the true colors…you have to go with what they are connected to at the furnace board.

more than likely they connected those wires wrong and that’s causing your issues. normally you wouldn’t have that splice…that’s interesting. it might even be worth it to have someone come run a new wire set, and they would just throw the thermostat on for you too. . its usually a pretty straight forward process running those wires if you decide to go that route. it shouldn’t be expensive. I think it was going to cost me about 40$ when I was thinking about doing it myself.

hope this info helps in some small way.


The white wires come from the adapter at the control board. The colored wires in the adapter (I think) are from the thermostat. There’s also some other wires at the board that look to be for other things.

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Since you re using the C-Wire Adapter, did you connect G to C on the Wyze backplate? G becomes C when using the adapter.

Hi Brian,
I have tried that, someone on reddit said that my furnace might already have a C wire?

I attached the photo of the original wiring on the furnace and the wyze backplate.

Thanks for the photos, your furnace has a C terminal with a wire attached which is most likely going to your A/C outside with the additional wire in the Y terminal.

You are missing the C wire on the Wyze backplate and will need the included C-Wire Adapter. Once the adapter is installed, move G to C on the backplate.

Rc should have jumper to Rh at the Wyze thermostat wall plate. however, you have red wire going to Y on furnace board wiring is not conventional.

you have a blue wire at wyze plate not connected?.

You may want to trace the wire from furnace control board to the splices to original wire heading to upstairs thermostat.

thermostat wire that goes inside furnace must be 105C rated by code. The white wires may be 60C rated. Should check to confirm.

Definitely see if you have an extra wire. If you do, just wire everything as it was before and connect the C wire on both ends.

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This helped and I also had to move Rh to Rc and now it is working properly, thanks for the help :smiley:

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I just got my thermostat as well and I am having a bit of trouble myself. I think I am doing something wrong with the adaptor and the heater. I moved g to c at thermostat but still no Wyze logo on screen.

On the heater end I do have two wires going to c and y like discussed above goes to ac. Not sure if that is part of the problem Any help would be much appreciated.

Hello @Peanutmms

Try moving the Rh to Rc and see what happens.

I moved the RH to RC still no luck. Thanks for the suggestion. I swear I hear a click each time I reconnect the face. But nothing on screen a


It looks like you have a Blue wire wrapped around the wires hooked to the C adapter. If so, use the Blue wire to wire in C at both ends and forget using the C Adapter. Go back to your original wiring at your air handler (furnace) with the addition of the Blue C wire and to C on Wyze plate. Also, Red wire goes to Rc on Wyze plate. Without the C Adapter, Green goes from C to G.

Hi Jwn, I do not have a blue. I have red green white yellow. The old thermostat was set up with G Y W RH with a black wire going between rh and rc. I had nothing connected to C

I am up and running thanks everyone!

What was your fix?

What was the fix??