Thermostat Problems

I was trying to setup the thermostat today, and validated that it works with the current wiring.

Here is my initial wiring

Here is the second (wyze setup)

First issue it ran into was saying its missing the O/B connection.
Even though its plugged into according to the Wyze included a diagram for wires provided.

I have an A/C unit outside, and FAU in the attic (Townhouse).
Not sure on any of the specs of these things though, I could probably find them if needed.
It ran through the test
Failed Heat 1
Passed Heat 2
Passed Heat 3

But it looks like its using the A/C now when its trying to heat, and cooling. Heat worked for a minute.

Not sure what to do right now, as I need to get this up and operational ASAP.
I took the front off the device for right now as I am unsure what to do.

Here is the setup with the wyze

First, let me say that I am not an HVAC individual, I am a DIYer and have hooked mine up myself. With that said, I have a quesiton or observation:

1, Based on the wiring, I assume you have a Heat pump, correct?

2, Sounds like it is not providing heat but kicking on the A/C, correct?

Just getting my mind wrapped around this.

With that said, when you setup the T-Stat you indicated it was a heat pump, once you do that and you get to the main screen there is a setting which allows you to switch the B/O for Heat or A/C.

Here is what I found searching the Forum:

"settings>advanced and select “swap hot and cool”

@speadie , any other suggestions?

Not even sure, should I reset the device? I remember it said something about electric vs gas.
Its in my attic so not 100% what it is.
I know on my breaker box it says FAU (Forced Air Unit)?

The way to tell is to go outside to your fan / Compressor. On a Heat Pump, it will turn one way for heat and another for AC.

On a conventional system, the AC Compressor is outside and the heat is in the HVAC unit like Gas.

Electric would be a baseboard of sorts or something similar.

Not sure if a Heat pump is considered Electric.

Can you provide the model number of your HVAC System?

Believe the furnace: [

Lennox Furnace Model G51MP-36B-045-1

Thats what the neighbor see’s on his, cant access my crawl space that easy, but we are all in townhouses. Would expect to have the same thing. Outside is a Central Air Unit (Carrier is on the label). Its old, cant find any marking for model. Can get a picture of it if needed.

corection G40UH-36A-070X-03 LENNOX

It’s unlikely you have a heat pump. That B wire is probably not actually connected to a reversing valve. I’m not sure what it’s connected to, if anything, Without a picture of the furnace side of the wires, I can’t be sure, but it should be ok to omit it for now,

You should reset your wyze and tell it you have the following wires: Rc, C, W, Y, G.
Your heat source is gas.


Ok that seems to work currently. It failed the “test” but I think I was impatient, and didn’t let it run before clicking no. Cooling turned and worked, then set it to warm the house (house was at 66, so bumped it to 69 for testing).

Should I try and get an image of the wiring, I have the manual, but that also does not show a B line attached. I can upload the image

Thanks for the information here. How did you pick up that it was not a Heat Pump? More out of curiosity so I know next time.

As usual, thanks for the assist in this.

So this does not seem to actually work. I have not “schedules” the thermostat is off, but its still heating. I had to pull off the to top to make it actually stop. Any idea? I know there is a like a cool off but it was going for like 5 minutes or past when I said for it stop. @ [speadie]

Hmm? If the thermostat isn’t calling for heat, it shouldn’t keep heating. When you rewired it, did you reset it and tell it your wires over again, or did you just rewire it?

I never rewired the device, I just input what you stated in the previous post. I don’t know I read somewhere that it could just be the fan running after the heater shut down, and I was getting inpatient, need to I guess test it a bit more.

I know other folks who have nest/ecoobee in the neighborhood whos setup was super easy, seems like wyze is a little more complex.