Hi there!
Thanks for posting in the community.
I’m sorry for the inconveniences that you’ve been experiencing with your Nest thermostat. I understand that you just installed it the thermostat is turning on, and you are able to set a desired temperature on it, but the AC unit is not turning on. No worries, help is here.
To further assist you, I will need some information. Here are some questions for you:
- What is the model of the Nest thermostat that you own?
- Did you take any pictures of the wiring on the old thermostat?
- What is your HVAC system?
- When did cooling last work?
- Did you check the compatibility of your system with the Nest thermostats?
- Did you turn off the power to your HVAC system?
- Are the breakers turned on?
- Did you recently experience a brownout or blackout?
- Did you have any construction or maintenance work done on your home?
- Have you experienced extremely hot weather lately?
- Do you see a power error code on your thermostat?
- Have you installed a common wire on your thermostat?
- Did you install it by yourself?
- What troubleshooting steps have you taken?
In the meantime, you can try the next steps to restart your Nest thermostat:
- If it is a Nest Thermostat E or Nest Learning Thermostat, follow the next instructions:
- Press the thermostat down until the screen turns off (about 10 seconds), then release.
- Press and release the ring to turn the screen back on and complete the restart process.
- If it is the normal Nest thermostat, follow the next instructions:
- Pull your thermostat off its base.
- Remove both AAA batteries.
- Replace the batteries and press your thermostat onto the base until it clicks into place.
- Your thermostat will take a few moments to turn on and restart.
If the restart doesn't fix the issue, try our thermostat troubleshooter for more detailed help.
In the meantime, you can check the following articles for further information: Troubleshoot strange heating or cooling behavior.
Tell me how it goes.
Regards,
Daniel.