I understand. Based on the image you sent, your baseplate wiring only
has two wires: R and C. This means that you have a single-stage heating
system.The Nest thermostat is a multi-stage thermostat, so it will not
be compatible with your existing wiri...
The Honeywell THX9421R02 and Nest thermostat have some differences,
notably in the wiring. For your specific setup, try connecting the Nest
thermostat with the following wires:- C: Common wire- R: Power wire- W:
Heating wireYou can leave the Y wire u...
