Thermostat green wire issue

I installed my thermostat and it repeatedly tells me the green wire, which control the blower is not connected. The green wire is connected and when I connect my old thermostat it works fine. When I run it with the Wyze thermostat the blower will come on with the heat, but not when cooling. I know the wiring is correct. Anyone have this issue?


I am having the same issue. It keeps telling me the green wire (G) is “missing”. I can’t figure it out. I have started the process over 5 times and still nothing. Old thermostat worked and works fine, but I can’t figure this out!


Same issue for me. I’ve checked the wire on both ends and it is secure. If I go through the setup and tell the app that I don’t have a green wire then all works. I also tried to disconnect the c wire and use the c wire adapter but that also didn’t work (wouldn’t even power the tstat).

If you tell it you don’t have a green wire it let’s you past the set-up, but does the system function okay after that?

Yes. But I don’t have the full functionality of the unit. The g wire controls the fan I think.

Sorry. Let me try that again.

Yes it lets me past the green wire issue in the app.

No the unit does not function properly. Heat and fan are not coming on. Ac seems to work fine but I think that’s expected as the y wire controls ac.

Same here. I can bypass the app/device not detecting the G Wire, but we don’t get heat

Thanks for replying here. Hopefully we can get some feedback from a Wyze support person since we seem to have a hardware issue.

Do you have a photo of the Wyze backplate when you wired it?

I don’t since i had to hook the old one back up. My system is very straight forward though. blue wire for C, Green wire for G, Red Wire for RC, White for W1, Yellow for Y1. My old thermostat uses a jumper from RC to RH, which Wyze tells me not to use. Other than that, it’s exactly the same.

That is odd that the blower would only run in Heat. You did the System Test in the app?

Yes. If I bypass the “missing green wire” in the app and go straight ahead to the test, the heat comes on and blower runs, Then it tests cooling and outside fan and compressor come on, but the blower never does.

Here was my back plate.

Any update on this issue ? I’m having the same problem.

Zero update. I’ve reached out to them directly and not heard anything yet. It sure seems like a hardware issue to me.

Same for me. Today I called a number for Wyze Wizards I found on the internet and all the tech could tell me was that escalation would be handled by a tstat specialist and they would get to it as soon as they could.

I have a single furnace & ac but three zones so I bought three thermostats. One of the thermostats was working at one point (although has since stopped because I deleted the configuration that was working and can’t get it to work now). This thermostat had no c wire so installation required the c wire adapter which then converts the g wire at the furnace into the c wire at the tstat. So for the working tstat I only had Rc, Y, W and C.

I tried this same approach for the other two thermostats even though they have a c wire. I used the c wire adapter at the unit (basically disconnecting the actual c wire and connecting the adapter) and then used the Rc, Y, W, C at the tstat. Wire checks work out ok in the app. Calls for heat and cool from the tstat are received by the unit but the blower doesn’t come on. I can’t actually tell if it is working since no air is blowing.

I’m about to give up and send them back.

Looks like I had an issue with my furnace that was causing the blower etc not to come on. I fixed it last night but it was too late to put that thermostats back in. Tstat was calling for heat / cool properly and unit was responding correctly (aside from a furnace flame fallout switch being tripped which was stopping power to the unit) so I expect everything to work.

Disconnecting the c wire will work which requires using the wyze c wire adapter to compensate. At the unit I’ll have RGYW from the tstat wire going into the adapter. The adapter will then send a signal to RGYWC at the unit. At the Tstat I’ll have RYWC. The only difference (app gives you this instruction) is that the g wire goes to the c terminal at the tstat. You will have to run through the app saying that you don’t have a c wire (eg R or Rc, Y, G, W… no C).

When I had this configuration things were responding well.

I’ll try to wire it all up once family stuff is done for Christmas. Merry Christmas y’all!

I installed the thermostat with no C wire adapter. The setup told me to unhook green as “extra”, With this, the A/C and furnace were running at the same time. My only fix right now is to disconnect A/C completely from the circuit board.

The system must be using Yellow to control the fan but this also makes the A/C unit run unnecessarily. How do I get the Wyze to acknowledge Green for fan control and Yellow as only A/C.

Let me know if this works… Disconnect the C wire at the unit and at the Tstat. Then go through the setup. It should tell you to use the c wire adapter if you select R/Rc, Y (cool), W (heat), G (blower) with no C.

Follow the directions for the c wire adapter. At the tstat, you should then be told to connect Rc, Y, W, and C (G goes into C). Then finish setup. This was working for mine.

If you don’t want to experiment, i’m going to try to same thing here when I get a chance.

Reading in other threads, using the c wire adapter doesn’t allow you to run the fan independently of heat or cool.

So I’ll wait to see what the formal response is.