I’m writing because I’m trying to replace my old Honeywell Thermostat with a new one. The old labels for the wires does not match what they are asking for with the new one. I’ve attached a pic of the old one wired up:

old thermostat with labels and wires attached

And a pic of the new one and the labeled wire terminals:

new honeywell thermostat terminals

Does anyone know where the wires should go?

  • Are you open to taking your new thermostat back and getting a different one instead? Jun 16, 2022 at 0:16
  • Have you considered consulting the manual?
    – Hot Licks
    Nov 13, 2022 at 2:56

1 Answer 1


Old thermostat is a Honeywell type.

It has an option to control the Fan speed.

New thermostat does not have that.

1 & 2 on the old are 24 Volts = R & RC on the new thermostat.

3 on the old is heating

4 on the old is Cooling

Now you have 4 more wires on the old used to control the Fan speed. Only one wire #9 on the new.


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