and whatever else he does. He also tests the temperature of the air coming out of the outlet.

I have never had an AC fail during the hot time of the year, or the cold.

Actually, I did have an AC unit fail once during the summer when I was renting a house out as an AirBnB while I was gone for two years.

Turns out the "visiter" had set the AC to 65 degrees in Arizona. It was only able to cool to about 75 degrees. In Arizona where it is over 110 degrees for several weeks during the summer, 75 is cooler than you can reasonable expect. So it didn't really fail, but just didn't turn the house into a refrigerator.