Nest thermostate not working

[TommyC64]

Where to I connect the Y2 wire on my Nest?

I am assuming that Y goes into the Y slot

[CoolingWizard]

@TommyC64 , in order to support the Y2, which is technically stage two cooling on the compressor, you have to have a smart thermostat such as the Nest Learning thermostat or the Nest E Learining thermostat.  

AC Cooling Wizard

[moralesvicente]

Hello TommyC64, 

Thank you so much for posting in this community. I understand you may be encountering difficulties installing the wiring system of your Nest thermostat, in particular with the terminal Y2. So don’t worry; I’m more than happy to help you.

To provide you with accurate troubleshooting steps, I would appreciate your assistance in answering the following questions:

• Could you please attach a picture of the previous wire system of your thermostat and the current installation?
• Do you see an error code on your thermostat? 

If you have any more information that could be helpful, please let me know. 

Best regards

Daniel