Need help to understand how do I wire this

[raghuganji]

Hello,

I am trying to replace my old honeywell thermostat with Google nest. I am having trouble with the wiring. Any help will be greatly appreciated. Please see the attached images of the old wiring and the new one.

After the nest setup, it is NOT recognizing Y and C and started recognizing the O/B as heat pump. Mine is a Gas Furnace. Not sure why it recognizes the OB as a heat pump. 

I mapped G to G, R to R, B to C, O to OB, W to W and Y to Y. 

HoneywellNest

[zoeuvre]

Hi raghuganji, 

Thanks for reaching out to us, and I'm sorry to hear about the situation. Let's sort this out.

The *OB terminal is responsible for a heatpump system. Since you have an O terminal from your previous thermostat, it should go to the *OB terminal of your Nest Thermostat. You can learn more about thermostat wires in this article. On the other hand, make sure that the Y and C wires are properly connected to their respective terminals with no loose or exposed wires. Please turn off your power breaker first before making sure that all the wires are properly connected.

Let us know if you have any other questions. We're happy to help. 

Best,

Zoe

[raghuganji]

Hello, As my mentioned in my post, mine is not heat pump. It’s a gas furnace. If I connect OB with O then it’s recognizing that as heat pump, which is not correct in my case. Thank you 

[zoeuvre]

Hi there, 

Thanks for getting back to us. Can you tell us what is the make and model of your HVAC system? Also, please send us a photo of the other end of your thermostat wires connected to your HVAC control board. 

Regards,

Zoe

[raghuganji]

Hello,

I took some pictures of my HVAC wiring. Attaching the pictures. Please take a look. Thank you for your response.