Nest Thermostat to replace a Carrier thermostat

[SY4]

The letters on the Carrier thermostat don't match with the Nest. The Google Home App indicated incompatibility between the two thermostats. I want to give it a final try before giving up. Please see the wiring in the Carrier thermostat. 

[CoolingWizard]

The wires you are currently using are:

R - Red Wire (Power 24VAC)

Y - Yellow Wire (Cooling Relay)

W - White Wire (Auxiliary Heat)

G - Green Wire (Fan Relay)

C - Blue Wire (Power Common 24VAC Neutral)

O - Orange Wire (Heat Pump Changeover Valve)

The AC Cooling Wizard

[Markjosephp]

Hi folks,

I wanted to ensure that everything was covered here.

Thanks for creating a wiring guide for the user, @CoolingWizard.

@SY4, I hope you've found the answer you're looking for. You can follow the wiring setup mentioned above as a guide. If you're still in need of assistance, feel free to let us know.

Regards,
Mark

[SY4]

Yes, @CoolingWizard's wiring was very helpful. Thanks. 

[Markjosephp]

Hello SY4,

I appreciate you getting back to us. I'm glad to hear that it's now sorted out and working. It looks like we can consider this one complete, so I will lock the thread within 24 hours unless I can help out with anything else.

Regards,
Mark

[SY4]

Thanks for the explanation. Sorry, it took me several days to get it back. After following the label you provided, I was able to install the Nest. It is up and running now. Thank you.