Nest Learning Thermostat won't engage compressor

[grinch]

When my old Honeywell thermostat is installed, the cooling and heat work just fine, so I know it is not an issue with the system itself. When I installed the nest learning thermostat it would connect to everything and set up just fine, except the cooling and heat were switched. when i tested the cooling, the heat turned on, and vice versa. I switched the heat and cooling wires and it still had no fix, except the ac compressor would not engage. i disconnected the nest and reconnected my previous thermostat to test the system again, and the system worked fine and the compressor engaged. any ideas of what is happening or how to fix it?

[ovidioj]

Hello @grinch,

Thanks for posting in the community. 
I appreciate the details about the issue you're experiencing with your Nest thermostat. To effectively troubleshoot this, please provide the following information:

• HVAC System Details: Please provide as much detail as possible about your HVAC system, including the manufacturer and model numbers of your furnace, air conditioner, and heat pump.
• Wiring Configuration: A clear photo of the wiring connections at your thermostat would be helpful. (new wiring configuration and old one).
• Nest Thermostat Model: Please specify the exact model of your Nest thermostat (e.g., Nest Learning Thermostat, Nest Thermostat E). Or send me a photo of your Nest thermostat. 

With this information, I can better understand the potential causes of the issue and provide more accurate troubleshooting steps.

I appreciate your cooperation and look forward to assisting you further. Thank you.

Regards, 
Jorge