AC unit turns on/off by itself

[WilliesMom]

We had to get a new AC unit installed last week. After it was complete we noticed the exterior fan was running continuously and not turning off despite what the thermostat said.  They came back out and switched two wires on the outside unit and it seemed to work correctly. Then that night we noticed that the outside unit would turn on by itself, even if the AC was not turned on in the house and the thermostat did not show it was on. Air was not being blown into the house. Just the fan was running in the unit outside. This is now the fourth day that it has been doing that. We’re trying to figure out if this is an AC unit problem or a nest thermostat problem. Thanks for your help

[luciaaa]

Hi @WilliesMom,

Thanks for reaching out to the community. I’m sorry to hear that the outside unit is turning on even when the AC is off. Thank you so much for all the information provided. I'm happy to assist you.

To better assist you, I have some questions about your device:
 

• What type of thermostat do you have? 
• Would you mind sharing a photo of your wiring configuration?
• Do you have a conventional or a heat pump system?
• When did your system last receive a professional maintenance check?

In the meantime, here are a few things you can try:

• Before you start, please turn off the breaker for your HVAC system.
• Check if the air filter is clean and replace it if necessary.
• Check if the drip pan is not overflowing.
• Check if the drain tube isn't clogged.

Keep me posted.

Best regards,

Ana.