topic Re: Only R and C wires on Honeywell thermostat in Nest Thermostats

Only R and C wires on Honeywell thermostat

Young — Sun, 19 Dec 2021 13:44:25 GMT

I only have R and C wires attached to my old Honeywell thermostat. There are white, blue, and yellow wires, but they are not attached to anything. I have 2 zones, each with separate HVAC units and thermostats. The one on the main level is working fine with Nest. This 2 wire one is in the bedroom upstairs. Thanks in advance

Re: Only R and C wires on Honeywell thermostat

MadGasser — Sun, 19 Dec 2021 19:29:51 GMT

What type of heating system do you have?

Re: Only R and C wires on Honeywell thermostat

Young — Mon, 20 Dec 2021 03:53:26 GMT

Gas

Re: Only R and C wires on Honeywell thermostat

MadGasser — Mon, 20 Dec 2021 12:09:53 GMT

I'm assuming you're taking a gas furnace. What were need to do is locate your furnace and open on panel where the thermostat where's connect. We need to see what wires are landed on the control board.

Re: Only R and C wires on Honeywell thermostat

Young — Mon, 20 Dec 2021 14:47:00 GMT

Yes, it is a gas furnace. I will take a picture of the control panel and post it in a day or so.

Thanks

Re: Only R and C wires on Honeywell thermostat

Young — Tue, 21 Dec 2021 01:35:49 GMT

Re: Only R and C wires on Honeywell thermostat

Young — Tue, 21 Dec 2021 01:39:10 GMT

Re: Only R and C wires on Honeywell thermostat

Young — Wed, 22 Dec 2021 09:55:15 GMT

OOPS. I had uploaded the wrong unit's control panel pics. Here are the correct ones. The HVAC is American Standard Model 4A7A4024L1000BA.

Re: Only R and C wires on Honeywell thermostat

MadGasser — Wed, 22 Dec 2021 10:52:10 GMT

Are there any other wires in the bundle in the wall?

Re: Only R and C wires on Honeywell thermostat

Young — Wed, 22 Dec 2021 12:32:19 GMT

White, green, and yellow. Thanks

Re: Only R and C wires on Honeywell thermostat

MadGasser — Wed, 22 Dec 2021 22:22:54 GMT

So hook them up to your nest according to color. W(hite), R(ed), Y(ellow), G(reen), and put the blue on the C terminal.

Re: Only R and C wires on Honeywell thermostat

Young — Thu, 23 Dec 2021 13:15:39 GMT

It turns out there is a Honeywell panel attached to the HVAC unit. The current thermostat is of Honeywell. The white, yellow, green wires that were not connected are really not connected on this panel. Thanks.

Re: Only R and C wires on Honeywell thermostat

Glide1989 — Mon, 17 Jan 2022 04:10:27 GMT

So what eneded up happening here did you get the nest working with your set up I am having the same problem only I am less educated in this department as your self. Thank you in advance

Re: Only R and C wires on Honeywell thermostat

Young — Thu, 20 Jan 2022 17:55:30 GMT

No resolution at this point. I think I need to hire a Nest Pro

Re: Only R and C wires on Honeywell thermostat

Hugo1 — Mon, 28 Mar 2022 04:15:12 GMT

Did you get to work? Did you rewire anything?

Re: Only R and C wires on Honeywell thermostat

Ccclaw13 — Sun, 17 Apr 2022 13:37:30 GMT

None of the smart thermostat companies have a guide on this and it would be really helpful too. I returned my smart thermostats bc I couldn't figure this out. I'm sure it would be easy with a guide and explanation. These systems are being installed in new houses like mine so I'm not sure why there isn't a guide already

Re: Only R and C wires on Honeywell thermostat

Blairhuffman — Sat, 04 Jun 2022 21:20:41 GMT

Do you guys still need help? I’m an HVAC Tech and know how to solve this.

Re: Only R and C wires on Honeywell thermostat

BGibson — Thu, 16 Jun 2022 18:19:30 GMT

Yes, please share. Trying to swap out a Honeywell as well.

Re: Only R and C wires on Honeywell thermostat

Pra31688 — Sun, 19 Jun 2022 02:16:45 GMT

I’m having the same issue. Can’t tell if it’s even compatible.

Re: Only R and C wires on Honeywell thermostat

Blairhuffman — Sun, 19 Jun 2022 03:15:57 GMT

So go to your furnaces control board. Depending on the stage unit you have youre gonna have 5, 6, or 7 wires:

R,C,G,W,W2,Y,Y2.
Take a picture of the colors going to each terminal, and put the same color wires to the same terminals

so say the Green wire is going to G terminal, put green to G on thermostat

if brown is going to G terminal on the furnace, put brown to G terminal at thermostat.

each unit may have different variables, such as, zoning systems, different upgrades to the system, etc. if there are different terminals the wires are going to besides the ones I mentioned, let me know.