Can GE Single Zone Thermostat GE89FR Replace Coleman Mach 4-Wire Thermostat?

Updated 04/16/2026 | Published 04/03/2026

Question:

It appears this thermostat is setup with 3 wires. I have a coleman mach thermostat setup with 4 wires B, A, VCC, COM. The coleman mach has fan mode, heat mode, and cool mode. The fan has low auto and high setting as well. My question is would this thermostat be compatible to replace. Thank you for your help.

asked by: Jason

Expert Reply:

Hello Jason, thanks for reaching out. No, that GE # GE89FR thermostat is not going to be a direct swap for your Coleman Mach setup.

The GE is a communication-style thermostat, not a traditional wire-by-wire system. It only uses 3 wires (power, ground, and a communication signal) and is designed to talk to a specific GE control box that actually runs the AC and furnace.

Your Coleman Mach thermostat is the opposite. That 4-wire setup (B, A, VCC, COM) is part of Coleman’s own control logic, where each wire has a defined function and ties directly into their control board. Those systems aren’t interchangeable because they don’t “speak the same language.”

So even though both thermostats have similar features like fan speeds, heat, and cool modes, the wiring and control strategy are completely different. If you’re trying to upgrade or replace your Coleman thermostat, you’ll want to stick with a Coleman Mach compatible model or something specifically listed as a replacement for your control board.

expert reply by: Jesse M

Tim G.

4/16/2026

I wouldn't try it, GE thermostats work with a GE controller, and the controller is specific to the upper unit , and GE has a new Rev on their AC's. so, you can't intermingle different Rev models, so the 3 parts (the thermostat, the controller and the upper unit) have to be match according to the Revision

Jesse M.

4/16/2026

@TimG Hey Tim, yes, you are absolutely right. The GE thermostat would not work with a Coleman controller. Especially if the Coleman controller was made before 2025. It's never a good idea to mix and match AC system parts like that. Thanks for taking the time to share!

Tim G.

4/16/2026

@JesseM, and you can't treat the G.E. ac s at least the heat pumps, like we could the Colemans. You can't just change the top units, you have to change every component

Jesse M.

4/16/2026

@TimG Yes you are 100% correct. Any AC unit made after 2025 uses a different refrigerant type so they are not backwards compatible with any equipment made before 2025. You have to swap out the entire system rooftop unit, controller, ADB and thermostat.