topic Is my HVAC system wiring compatible? in Nest Thermostats

Is my HVAC system wiring compatible?

jakelw96 — Sun, 28 Nov 2021 23:18:08 GMT

Hi guys, I am just wondering if my system is compatible with the nest? It looks like the wires are soldered on. I am completely new to this and not sure if I can take those off without breaking them.. I’m considering calling a Nest Pro, but I want to know if it will be worth it or not. Compatibility checker said my system may be compatible. I have attached two images below. Thanks

Wiring set up 1

Wiring Set Up

Re: Is my HVAC system wiring compatible?

Patrick_Caezza — Fri, 03 Dec 2021 04:56:41 GMT

The actual connection is made at the gray wire nuts and not at the terminals on the thermostat. You should be able to carefully pull all of those connections out from inside of the wall.

Any of the Nest thermostats will be compatible with your system as it looks like you have a conventional heat/cool 4-wire system.

Re: Is my HVAC system wiring compatible?

jakelw96 — Fri, 03 Dec 2021 06:30:54 GMT

Oh hell, I feel dumb ha! I’ll give it a shot. Thanks friend!

Re: Is my HVAC system wiring compatible?

maristo — Thu, 17 Feb 2022 22:31:05 GMT

I want to install a c-wire, but my system (an old oil furnace) does only has 4 connections - two for fan, two for thermostat. That's it.