topic Re: Nest thermostat wiring in Nest Thermostats

Nest thermostat wiring

otilioster — Fri, 08 Dec 2023 03:22:15 GMT

My current system has both b and o wires, the nest thermostat has the o and b in one slot, how should I proceed?

Re: Nest thermostat wiring

CoolingWizard — Fri, 08 Dec 2023 05:57:38 GMT

@otilioster , when you have a B terminal and an O terminal being used, you have a heat pump and the B terminal is used as power Common. This is very true when the thermostat does not have a C terminal.

AC Cooling Wizard

Re: Nest thermostat wiring

otilioster — Fri, 08 Dec 2023 06:03:35 GMT

Thank you! So how would I wire it to the nest thermostat in this situation? Do I leave one of the wires disconnected?

Re: Nest thermostat wiring

otilioster — Fri, 08 Dec 2023 06:04:14 GMT

@CoolingWizard

Re: Nest thermostat wiring

CoolingWizard — Fri, 08 Dec 2023 06:09:47 GMT

Just put the wire on B on the Nest C and the wire on O to the Nest O/B.
Your wires will be Rc, G, Y1, O/B and perhaps AUX/W2. Can you upload a picture of your current thermostat showing the connected wire.

AC Cooling Wizard