Wyze Thermostat Problem - AC on with Heat

Does your old thermostat work if batteries are not installed in it?

We triggered heater and AC bypass Wyze Thermostat, Our HVAC works fine. So it concludes that the Wyze Thermostat we got is not working. It turns on both Heater and AC.

Usually this is caused by improper wiring or install. Share your pictures of thermostat and furnace wiring if you want assistance.

Same here. We kept all wiring and did a jump test without thermostat, it triggered Heater correctly without starting AC. It approves that wiring is fine, but our Wyze thermostat sends wrong signal to the control board. Changed back to our old Honeywell, works like a charm.

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I put the wyze one back on and still the same. Trying to avoid the c adapter because I have a c wire already.

Does your non-wyze thermostat work without batteries? I’m thinking your common might not actually be a continuous run, it might go through your AC unit… This would cause the wyze to cause the ac to turn on when anything is drawing enough current, because the wyze only powers itself through the transformer.
If your other thermostat works properly, even without batteries, then I’m leaning towards a fault with your wyze thermostat. Or it thinks you have a heat pump for some reason.

I hooked up the non-wyze thermostat again and this time without batteries. AC and heat work as they should and the same with or without batteries.

Is this telling me my wiring is correct and the wyze thermostat is bad? I’ve tried factory reset, but is there settings I am missing?

Thanks for all the help.

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I am having the exact same issue, when i hook my old one back up it works just fine.

You can check out this YouTube video to get more information on how to manually trigger your heater and AC and give it a try to see whether your wiring is correct. Heat and Cooling Running at the Same Time - YouTube

Thanks for the tip! My fan also was coming on early, and blowing cold air (at high speed) in the process. I disconnected the G wire and now the furnace heats up the heat exchanger box first before the fan kicks in. And the fan is on low speed like it’s supposed to be.

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That’s what is sounds like to me. Did you get an app update? Apparently that fixes things for some people, otherwise I’d contact support and tell them your wyze is defective.

Does your old one use batteries, or did you somehow manage to tell the wyze that you have a heat pump?

I did get an app update after adding it the first time. And my old thermostat did have batteries but worked with and without those. Right now I have the old thermostat hooked up until I can get a solid fix or something to try. I reached out to wyze for support as well. Also, hooked it up twice, both times not choosing heat pump.

Check the settings in the app. Under advance, there is an option to swap heat and cool. I think it has something to do with O/B for the reversing valve.

Heat + AC. That’s a new feature Defrost Mode. Use it to keep the windows clear and reduce the chance of a collision when it’s icy outside!

Yea thinking more people are having issues than not. I have two as gifts plus mine and all three are having the same issue as everyone else. I have contacted support. And as to my surprise no one has reached back out about the issue. This has really changed my mind n the products and service of Wyze. And not in a good way either.

Have you asked for assistance here? I’ve helped a ton of people resolve their issues. A lot of the problem with heat running while ac is also running is due to people not understanding how the system should be wired, or install techs being lazy and not running separate Y and C wires from the outdoor AC to the thermostat. If you are using the adapter, and your compressor is connected upstream of the connector, between the thermostat and the wyze adapter, then whenever your heat comes on, it will switch Y to G to turn on the fan, but because your AC is in that circuit; it gets turned on as well.

here’s how it should be wired:

And here’s how some companies wire it
This will cause the AC compressor and outdoor fan to run whenever the Y wire has electricity, and because the wyze C adapter uses the Y wire for fan during a heat cycle, this will cause the problem that people are having.


If old stat was wired so red is Rh why wire it into Rc on the wyze? Does all say to do that?

I’m still using my old thermostat until I get a solid fix or something new to try. Have not heard back from support as well. Speadie you have been helpful, but I’m still stuck with my issues. Wires look correct, no c adapter and separate AC wires to the outside unit.

Rh it shows to wire it as Rc with no jumper. Also my wyze thermostat would not turn on when wired to just Rh.

Wyze powers itself off of Rc and C, not Rh. it will switch Rc to cooling and heating if Rh is not present, or if Rh is present, it will switch Rc to cooling and Rh to heating.