Air Conditioner Won't Turn On: Checklist

A dead AC unit is most often power, a thermostat issue, or a tripped safety switch — run through this list before assuming a compressor failure.

By Tobias NwosuSeptember 25, 20253 min read read

Written by Sawyer Kincaid, Lead Technician — True Fix Houston. Factory-trained, EPA-certified, 6 years servicing Greater Houston.

Before jumping to conclusions about a failed compressor, rule out the everyday reasons an air conditioner won't even start.

Check Power and Breakers

AC units are notorious for tripping breakers and GFCI outlets, particularly right after a power surge.

Fix: Reset the breaker and test the outlet; window units also typically have their own built-in reset button.

A thermostat set incorrectly, or one running on dead batteries, simply won't call for cooling.

Fix: Set it to cool mode below the current room temperature and swap in fresh batteries.

Most units build in a short delay after a power interruption specifically to protect the compressor.

Fix: Give it about five minutes after power comes back before expecting it to start.

Not sure what's wrong? Book online — every visit includes a free diagnosis.

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