topic Re: OB Wire for Thermostat Not Detected in Nest Thermostats

OB Wire for Thermostat Not Detected

Harding17 — Mon, 01 Jan 2024 20:10:08 GMT

I am trying to connect my new Nest Thermostat (we have a Heat Pump) and during the install process the device does the wire check - it detects all the wires except the Orange Wire connected to the OB wire slot. If I skip and go forward anyways, I only get cold air blowing from my system. Here is a pic of the original wiring.

https://imgur.com/HHYg0NB

Has anyone seen this before or have a recommendation (currently the Brown wire is unconnected)

Re: OB Wire for Thermostat Not Detected

Markjosephp — Thu, 04 Jan 2024 20:42:53 GMT

Hello Harding17,

I'm sorry to hear about the issue you're experiencing with your Nest Thermostat installation. It seems like the OB wire detection is causing a problem with your heat pump. Let's troubleshoot this together.

Firstly, double-check that the orange wire is securely connected to the OB terminal on both ends (at the thermostat and the HVAC system). If it seems secure and the issue persists, there are a few things you can try:

Turn off the power from your HVAC system at the breaker before touching the wire.
Disconnect the orange wire, wait a few moments, and then reconnect it firmly to the OB terminal.
Inspect the orange wire for any signs of damage, such as fraying or cuts. If you notice any issues, consider replacing the wire or stripping it.
Tell us the wiring report it shows and gather the power readouts on the Technical Info settings or in the Equipment settings, depending on the Nest Thermostat version you have.

Keep me posted.

Best regards,
Mark

Re: OB Wire for Thermostat Not Detected

Rew64 — Sat, 03 Feb 2024 15:16:09 GMT

I am having this same issue. What caused it?

Re: OB Wire for Thermostat Not Detected

Markjosephp — Sat, 03 Feb 2024 16:37:29 GMT

Hi Rew64,

Thanks for stopping by, and I'm sorry you're also having the same experience. To better assist you, could you give me more details on your situation? Also, please share with us a photo of your thermostat's wiring setup.

I'll look forward to your response.

Best,
Mark

Re: OB Wire for Thermostat Not Detected

vegas_man — Sun, 25 Feb 2024 18:48:16 GMT

I also have the exact same issue. If you find a solution, please post.

Re: OB Wire for Thermostat Not Detected

zoeuvre — Sun, 25 Feb 2024 22:37:37 GMT

Hi Rew64,

Uh-oh! I'm sorry to hear that you are experiencing the same issue with your Nest Thermostat. Have you tried to follow the steps provided by Markjosephp above? If so, how did it goes?

Thanks,

Zoe