Single-zone direct relay wiring. The most common RV thermostat replacement.
Airxcel (formerly Coleman Mach) uses simple relay-based wiring. Each wire directly powers ON your AC, heat, or fan. There are no communication protocols or signal wires to worry about.
This guide covers single-zone systems - one thermostat controlling one rooftop unit. If you have multiple zones or a 9 Series controller, check the guides in the sidebar.
Most installations take about 30 minutes. You will need a screwdriver and a few wire nuts.
Before removing your old thermostat, take a photo of the wires and terminal labels. This is your reference for connecting to the WalTech.
Don't rely on wire colors alone - colors can vary between manufacturers and model years. Look at the label grid on the back of your Coleman/Airxcel thermostat to confirm which terminal each wire connects to.
This is the standard Coleman Mach color scheme. Your colors may differ - always verify with the terminal labels.
| # | Wire Color | HVAC System |
|---|---|---|
| R | Red Wire | +12V DC |
| B | Blue Wire | Ground |
| GL | Green Wire | Low Fan |
| GH | Grey Wire | High Fan |
| Y | Yellow Wire | AC - Compressor |
| WHP | White & Black | Heat Pump |
| W | White | Furnace |
Use the Mounting Template (included in the box) to mark your drill holes and wiring cutout on the wall.
The WalTech has three connection points on the back: a Left 8-pin connector, a Right 8-pin connector, and a Middle RJ11 jack (Dometic only - not used for Coleman Mach).
All wire connections use a push-and-lock system. Strip about 1/4 inch of insulation, push the bare wire into the pin slot, and it locks in place.
Pin #6 needs to receive the same +12V power as Pin #7. You have two options:
Plug the +12V red wire into Pin #7. Then use the included black jumper wire to connect Pin #7 to Pin #6.
Cut the included jumper wire in half. Insert one end into Pin #7 and the other end into Pin #6. Then use a wire nut to connect both jumper ends to your +12V red wire. This keeps things neat and secure.
If you are replacing a home thermostat (24V AC system):
Turn the power back on (reconnect shore power or flip your battery disconnect switch). The WalTech will boot up in a couple of minutes. You will see the WalTech logo on screen while it initializes.
Once the WalTech boots up, you will see the initial setup screen.
The device may restart after completing setup. This is normal behavior - give it a minute to reboot and it will come back to the main screen ready to use.