topic Re: Aux wire? in Nest Thermostats

Aux wire?

JRock — Sun, 01 May 2022 15:21:19 GMT

I have an extra wire that I’m worried about where it will go when I install. I think it’s an AUX wire but it was previously labeled “E”? Current thermostat doesn’t use the wire labeled “C” but it’s there and taped. I’m going to post a pic

Re: Aux wire?

JRock — Sun, 01 May 2022 15:23:26 GMT

Re: Aux wire?

Patrick_Caezza — Mon, 02 May 2022 03:05:49 GMT

It looks like you have just a conventional system.

You can verify the wiring by comparing the thermostat to the terminal block on the control board in the furnace/air handler.

I see a C label. Is that on the brown wire?

I guess that the wire labels are from a previous thermostat that this one replaced. SO I would suggest verifying the wiring before proceeding.

Re: Aux wire?

JRock — Mon, 02 May 2022 13:34:27 GMT

Yes, the C label is on the brown wire. I was wondering about that, because from what I’ve read it usually isn’t brown. But kinda assumed it was actually the C wire considering my current thermostat doesn’t use a C wire apparently.

Re: Aux wire?

Patrick_Caezza — Tue, 03 May 2022 04:24:05 GMT

Never trust the wire color as there is no standard.

Re: Aux wire?

MelbaDT — Fri, 06 May 2022 08:09:20 GMT

Hey folks,

Thanks for your expert advice here, Patrick_Caezza.

JRock, I want to ensure everything is covered here. Let us know if you have more questions.

Best,

Melba

Re: Aux wire?

JRock — Fri, 06 May 2022 18:54:42 GMT

I don’t live at the residence with the thermostat I’m replacing so I have t been able to check the terminal yet 😬 sorry for the delay AND thank you for the help!!

Re: Aux wire?

MelbaDT — Tue, 10 May 2022 02:23:29 GMT

Hey there,

Got it and thanks for letting me know — there's also nothing to feel sorry about. Feel free to reply back as soon as you're able to, we'll always be here.

Best,

Melba

Re: Aux wire?

MelbaDT — Tue, 24 May 2022 07:02:38 GMT

Hey there,

It's me again — how's it going now with your thermostat? Have you had the chance to get to the device's location?

Best,

Melba

Re: Aux wire?

MelbaDT — Fri, 27 May 2022 07:08:41 GMT

Hi,

I haven't heard from you in a while so I'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.

Best,

Melba