My home had an old, simple Honeywell thermostat that was working completely fine. See the photograph attached for wiring information. I am in Texas, so I have both an external AC compressor and a furnace, with a forced air system.
I bought an Amazon Smart Thermostat and wired it exactly as shown in the other diagram attached: blue wire in the C terminal, yellow on Y, green on G, white on W and red on R. There is a switch to the left of Rc that, when pulled up, is supposed to short R and Rc, effectively making them the same. This switch is up.
My issue: heating and fan work perfectly, but the compressor never turns on when the AC is activated. If I set the thermostat to cooling, the fan will turn on but the compressor doesn't run at all.
For testing purposes, I also:
- Bought another Amazon Smart Thermostat (in case the hardware was the problem). Same issue occurred.
- Tried plugging in the red wire straight to Rc. Same issue (didn't test the heating, though, but I assume it wouldn't work).
- Reinstalled the simple Honeywell thermostat I had before. The system works perfectly.
- Checked my other home, where the AC works fine with the Amazon thermostat; there, the white wire is connected to O/B instead of W. NOTE: the O/B and W wires appear to be the same in the Honeywell thermostat, but different in the Amazon Smart Thermostat. Wondering if I should just give this a try.
