I bought a house recently with a Nest thermostat. I usually get Honeywell or the Amazon one and install them, but I figured I’d just use the smart thermostat that was left. It had a schedule that kept coming back no matter how many times I manually cleared it (no wifi at the new house yet, so only setting it up as a dumb thermostat for now).
After three days of removing the schedule and it coming back, I decided to factory reset the thermostat in hopes it would fully remove it. Well it did, but it also seemed to ‘break’ functionality. I changed nothing with the wiring (yet).
The Nest did make me set it up as a dual-source system, even though I’m pretty certain it’s all only electric. And the colors it shows on the device don’t match what is wired. Which was where my confusion began. I know the colors don’t necessarily mean anything, it can be wired any way, so I just ignored it and moved on with the setup it “sensed,” assuming that since it worked before, it would work just fine now.
I came back to move more things today and it was 80 in the house with heat blowing. I turned the thermostat down to 72 and it heated the home to 85 before I noticed and just shut it off.
I checked the wires and tried to read the wiring diagram on the handler, and it only left me more confused.
I have 7 wires, as noted below, in the following slots:
- Yellow in Y1
- Green in G
- Blue in O/B
- Red in Rc
- White in W1
- Black in W2/Aux
- Brown in C
The wiring diagram on my air handler only shows 6 wires, and no diagram on the Nest instructions match my color wires, which is where more confusion came in.
Any idea why the reset would cause the setup to work wrong when it was working the day before with the same wiring setup? Does it have to do with the Nest recognizing it as a two-source system when it may be just one?
I appreciate any insight, I’d prefer to not have to buy a new thermostat if I don’t have to!
