Wyze Thermostat Install error - Extra wire

I tried to install the Wyze thermostat this weekend, and kept getting the error “Extra wire” for terminals Y2, W2, and *. I do not have wires in any of those connectors. I can click “Try again”, but it keeps coming back with the same error. I can close the Wyze app, and re-open it, then I see my Wyze thermostat. If I try to turn the Cool or Heat on, nothing happens, and after a few seconds the app goes back to “OFF”. I even tried turning on Hold. I tried 2 Wyze thermostats that I ordered, both have the same problem. I had to put my previous thermostat back in, as this was is completely non-functional. I have installed many thermostats over the years, and never had much of a problem. I am an IT tech myself, so I have reasonable experience with installing these type of things.

I live in Florida, my system is a pretty simple 15 year old American Standard heat pump system with backup heat strip for emergency heat.

Here is the error screen

Here is a picture of my Wyze thermostat wiring.

Here is the wiring from my current thermostat, a smart “Radio Thermostat” that I have been using for 6 years.

Here is a picture of my original dumb thermostat that was installed with my system to begin with.

When you tell the wyze what wires you have, are you telling it that you have those wires?
For a heat pump with heat strip backup, try telling the wyze app that you have the following wires:


You do not need to tell it about the jumpers on your old thermostat, that will just make it ask for those wires to be hooked up.

I did not tell Wyze about the jumpers.
I tried the install twice, once by selecting the wires from my current radio thermostat, and once by telling it the wires from my original, dumb thermostat.
Both times, the Wyze app told me to install the wires in the same order, as I pictured in my original post.
Here is what I told Wyze originally, coming from my current radio thermostat.

The wire detector gets confused sometimes apparently. I’m a little concerned about your wire insulation, it appears that the common wire’s insulation has fallen off farther down the wire and things might be shorting together which would cause an issue. What is the AC voltage between the Rc and C terminals?

There appears to be an unused black wire, is that present on the furnace as well? If you are not getting at least 25VAC between Rc and C, you might try switching that wire in for the common on the furnace and on the wyze- it’s possible that your blue wire has deteriorated to the point that it is not able to carry enough current to reliably switch the wyze’s relays. Does your other thermostat use batteries?

I don’t believe the problem is the blue wire.
The insulation is fine, I just scraped a little off trying to straighten the wires.
It has been re-insulated with electrical tape.
There are no shorted wires… everything works fine with my existing thermostat.

My existing thermostat does use batteries, so I will verify the voltage coming through the blue wire when I get home, good idea.

I am watching this… Having the EXACT same issue

Me too, identical situation as OP, except I am using his original dumb thermostat that has jumpers in the same places; mine looks identical. 15 year old Trane heat pump, living in Florida. I am an HVAC controls engineer with 20 years experience. I wonder if we know each other.

I am reading 27 vac between Rc and C. What exactly do you mean by switching that wire in for the common on the furnace and in the wyze? I only follow exact instructions; that way the manufacturer cannot blame me and void the warranty.

Also, I want to point out that the extra wires message appears without the wyze thermostat even wired up anymore. App seems to be telling lies.

Apologies if I am hijacking OP’s thread!

He has a blue wire with missing insulation, and all of his wires have insulation that appears to be cracking. he also has a black wire that appears to not be connected to anything, so my thought process was that he could try swapping that wire on both ends for the blue wire to eliminate any possible issues with the blue wire. If your only issue is that the wyze thinks extra wires are hooked up, then you can skip past that part if you press try again a couple of times. There might be some interference from the other wires confusing the wyze’s wire detection program.

Knowing that we are having the EXACT same issue, I would doubt that it is wire insulation. I tried MULTIPLE times to get past it by pressing the “try again” button but to no avail.

Wake Up Be Happy

Thanks for replying! The app was not letting me get past the “extra wires” screen no matter how many times I pressed try again. We both have an extra black and an extra brown wire not connected at the thermostat, if you have more ideas.

I am getting a steady 26.8v between C and Rc.
I don’t believe there is a problem with the wiring, as both of my old thermostats work fine.

The insulation is fine, the cracks you see are only at the end of the wires and were caused by using the rough needle nose plyers to get the wires into their spots. As I mentioned, I scraped the side of the blue wire trying to straighten it and have since wrapped that small part of the wire with electrical tape.

The app would also not allow me past the Extra Wires error no matter how many times I tried. As stated, I was able to exit the app, re-open it, then see the Wyze thermostat and attempt to use it. When turning the system to Cool or Heat, it would let me select a temperature, then a few seconds later it would change to OFF, even if I enabled hold. The actual HVAC system would never turn on in any way.

One thing I do notice is a ton of similarities between Destro’s situation, and mine:
We both live in Florida.
We both have 15 year old systems manufactured by American Standard (Trane is made by American Standard).
We both have the same original thermostat, wired the same way.
We both now have the same problem with the WYZE thermostat.

It sounds to me like there is some kind of compatibility problem with the WYZE thermostat and our type of system. What surprises me, is that our systems are very simple heat pumps, very common models, and made by one of the biggest HVAC manufacturers. I don’t see anything complex about our setups that should bother any thermostat. Newer HVAC systems are much more complex with more stages and features than ever before. I would think WYZE should work with the basic systems if it can be trusted to control more complex systems.

It looks like others are having the same problem.
I wonder if they have similar HVAC systems? :thinking:

I have a simular setup, same exact thermostat, I also got the extra wire message, and was able to skip and go into testing. It worked for me without any other issues, Also inside the app setup make sure you let it know you have an R wire, Not RC or RH. Your original thermostat was R.

What were the steps you used to skip this warning?

When you click try again, another tab pops up, and lets you click continue.

This was thermostat, I was replacing. My original “Dumb Thermostat” was the same as op as well…

I wonder if OP has a weird setup in the air handler. Maybe there’s some company that put a lot of them in weirdly in Florida around 2005…

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Not on mine, nothing would let me continue.
I am using Android, you?