Capacitors in August
Ask anyone in the trade what August does and the answer arrives before you finish the question: capacitors. The run capacitor — a soda-can-sized part that helps the compressor and fan motors start and keep spinning — is rated for heat, and an Alabama heat wave sits above its comfort zone for weeks. They fail by the thousands, all in the same fortnight.
- 1 Thermostat — The season’s odometer — a hundred cooling days pass through it.
- 2 Return and filter — The lungs, and the first thing a retrofit house sized too small.
- 3 Air handler and furnace — Up in the attic, asleep nine months, asked for everything in December.
- 4 Coil and condensate drain — Litres of Gulf moisture a day, all leaving through one narrow line.
- 5 Attic ducts — The coldest air in the house, commuting through the hottest room on the property.
- 6 Outdoor unit — Full sun, full load — where August culls capacitors by the thousand.
A part that dies of the weather
Capacitors age with heat: chemistry inside them degrades faster at the temperatures an outdoor unit reaches when it is both running flat out and standing in the sun. A capacitor that tested fine in May can be gone by the second week of a hot spell — which is why the failure has a season, and why the season is the exact moment everyone else’s has failed too.
The signature is distinctive: the outdoor unit hums but the fan does not spin, or the fan spins while the compressor never starts; sometimes a click, sometimes a breaker. Indoors, the blower moves air that is not cold. It looks like a dead system and is usually a forty-dollar part and twenty minutes — which is exactly why it deserves an honest diagnosis rather than a condemnation.
The conversation it should trigger
A failed capacitor on a young system is weather, not destiny — replace it and go back to summer. On an older unit it is worth one more measurement: a capacitor that died may have been straining a compressor for weeks first, and a technician who checks the compressor’s draw after the swap is doing the job completely. Repeat failures, or a capacitor that goes with a contactor pitted black, are the electrical system of an aging unit introducing itself.
The scheduling lesson is the same one this climate teaches everywhere: the spring look-over catches a weak capacitor by measurement, in April, when the calendar is open — instead of by failure, in August, when the whole state is calling the same phone numbers.