topic Re: Wiring question in Nest Thermostats

Wiring question

bushev — Sat, 18 Feb 2023 00:50:39 GMT

Hello,

I have replaced the old Honeywell TH3210D with Nest v3. I suspect I'm wired it incorrectly because the heat pump does not produce heat.

On the old thermostat blue wire connected to the Y terminal. As I read in the Honeywell manual, Y is a compressor (cooling), so I connected it to the Y1 terminal on Nest.

Then, I connected the orange wire from the O terminal of Honeywell to the "OB" terminal on Nest, as I understand that it is a heat signaling cable. But I'm quite unsure now.

Could you please point out my mistake please? 🙂

Attaching the old and new wiring as well as the Honeywell's specs.

Nest

Old Honeywell

Re: Wiring question

Patrick_Caezza — Sat, 18 Feb 2023 03:38:48 GMT

Try this wiring,

Black - E to * (set as emergency heat)

White - AUX to W2 (set as aux heat)

Blue - Y to Y1

Green - G to G

Orange - O to OB

Red - R to Rc

White/Black to C

Re: Wiring question

bushev — Sat, 18 Feb 2023 15:16:58 GMT

Sure, I added C wire, but unfortunately, it does not work...

Re: Wiring question

Patrick_Caezza — Sun, 19 Feb 2023 04:58:56 GMT

Post a picture of the terminal block on the control board in the furnace/air handler.

Re: Wiring question

Markjosephp — Mon, 27 Feb 2023 16:29:36 GMT

Hello there,

I wanted to ensure that everything was covered here.

Thanks for lending a hand, @Patrick_Caezza.

@bushev, I'm checking in to see if you were able to take a picture of your system's control board. This will help us move forward with how your thermostat is labeled.

Regards,

Mark

Re: Wiring question

Jenelyn_O — Thu, 02 Mar 2023 17:21:16 GMT

Hi there,

Chiming in — I wanted to follow up and see if you still need help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

Re: Wiring question

Markjosephp — Sat, 04 Mar 2023 15:37:18 GMT

Hello bushev,

It has been a few days since your last reply, and we're going to lock the thread within 24 hours. If you have any questions, please feel free to create a new post.

Regards,

Mark