Wyze Thermostat in an RV

So first off, I have to admit something; I am a Wyze Fan Boy. Now that that is out of the way, I will give some background on my situation.

Thanks to COVID my work schedule has changed to being in the office one week and work from home the next. Being in tech this is actually not a bad deal for me, and I have come to quite enjoy it. That said, I also have a wonderful…ly loud toddler at home to make sure that I am in a nice quite environment allowing me to focus, he said facetiously. Luckily, a few months ago we decided to buy a travel trailer and then parked it in the driveway. Welcome to my new office.

The trailer is great. It is quiet, comfortable, and has everything I need to be productive. Being the nerd that I am, I setup a server for development vm’s and internet via Starlink, which is awesome by the way, a great WIFI network, and even a cell phone booster. The only issue that I run into is thanks to the wonderful winter storms in North Idaho, and my desire not to waste propane by keeping the trailer 65 degrees, I come into the trailer for my morning meeting to a 50 degree trailer, brrrrr.

Enter the Wyze Thermostat. When I saw the thermostat get released, I decided that I must have it for the trailer. I mean the thought of having the ability to heat up the trailer before I go out was too good to pass up. After reading the specs I had a decent concern, 24 volts AC. But I want to use this in a trailer, with a 12v system, and I don’t want to use an inverter with a step-down transformer and use so much power for less than 1 amp of needed power. Well after thinking about it and discussing it with a friend who is much more adept with electronics than me, I decided to try powering it with 12v DC.

Guess what… It Worked! There you go that huge, long story just to tell you that you can use a Wyze thermostat with 12v dc in an RV. I will at least give you something in return. Below are the pictures and diagrams of how my system is wired. I looked everywhere online and found that others had the same idea as me for using the Wyze thermostat, but no one had apparently tried to, so I did it just for you.

TL; DR

Setup

Wiring

Wiring Color | Function | Thermostat Label

  • Green – Fan High –> G
  • Gray – Fan Low –> Not Connected
  • Yellow – AC Compressor –> Y1
  • White – Furnace –> W1
  • Red – 12 VDC + –> RC
  • Blue – 12 VCD – –> C

Warning!!!

*** Do not connect the Blue Wire to O/B *** It will blow fuses if you do.
Your devices all share a common ground on the trailer and do not need this to be connected. The thermostat is setup for AC power and does not handle the DC ground properly.

Fan Speed Note

The thermostat is only setup for one fan speed. I picked the Green wire for high fan speed. For my use case I will likely always want the fan to blow fast if I want it on at all. If you would like to be able to control the speed you can connect the green and gray wires to a SPDT switch and install that near the thermostat.

Coleman Mach Thermostat
Original Coleman Mach thermostat.
Back of original thermostat.
Back of original thermostat.
Wire connections from original thermostat to the wiring in the wall.
Wire connections from original thermostat to the wiring in the wall.
Wires from wall wiring to the Wyze thermostat base plate.
Wires from wall wiring to the Wyze thermostat base plate.

Thermostat Setup

Select these options to match your thermostat wiring.
Select these options to match your thermostat wiring.
Wiring error warning.
You will likely receive this error since the thermostat cannot sense the wiring. Just click “Try again”.
Wiring error warning options.
After clicking “Try again” the first time you should see an option to “Skip”. Go ahead and Skip.
Select your fuels type as propane.
Select “Propane” as your fuel type.
Select other the type of heat being controlled.
Select “Other” as the type of heat being controlled.
Thermostat Test
Notice that this says “radiator”.

Stats for Nerds:

Amp Draw

As reported by craigs92040 on the Wyze Forum:
Yellow 0.1 amps
Green 0,08 amps
White 0.15 amps