On Wednesday we had an HVAC company come by for a routine inspection of our air conditioner. When he was done, the guy (who was by far the friendliest maintenance person I've encountered) went over all the operating stats about our unit: pressure levels, temperatures, airflow, fan speed, system BTU, percent efficiency, amps, capacitors, etc. The takeaway was that our unit is operating almost perfectly across the board. He said he was impressed with how well it was running. Sweet.
He also convinced me to sign up for their club membership. Normally I decline, but rates went up and the membership now saves a decent chunk of money, rather than the small fraction it used to be. He left, and I felt good about our A/C and fairly pleased that I was now saving money.
Then, Saturday night, the A/C stopped working. And it was just in time for a heat wave: this weekend was the first in nearly 2 years to have back-to-back predicted highs in the 90s. The temp in our house was in the low 80s and only going up. So at 8pm on Saturday I called the HVAC company again. I explained the A/C had just gotten a clean bill of health, and that I was a member of "the club." Fourty-five minutes later a different repair guy was at our house, working in the dark to find the problem.
And within a half hour, he had found it: a bug. Specifically, an earwig. It had the gall to crawl into an electrical switch in our perfectly fine A/C, and was crushed when the unit tried to turn on. Its body then acted as an insulator that prevented electricity from flowing. Once it was removed, the A/C started up just fine. This was the first time such a thing had happened to us, but he said it has happened many times in his 20+ years on the job.
In the end, the dead earwig cost us $100.