Wiring question

[bushev]

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

[Patrick_Caezza]

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

[bushev]

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

[Patrick_Caezza]

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

[Markjosephp]

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

[Jenelyn_O]

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

[Markjosephp]

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