AC Won't Turn On: A Phoenix Homeowner Checklist

Blank thermostat? Silent outdoor unit? Work through these checks before you assume the worst.

Thermostat

• Set mode to Cool, fan to Auto, setpoint a few degrees below room temperature.
• Replace batteries if the screen is dead.
• If you have a smart thermostat, confirm it still has Wi-Fi/power from the C-wire or batteries.

Power

• Check the breaker panel for a tripped AC / air handler / condenser breaker.
• Reset once. If it trips again, leave it off.
• At the outdoor unit, confirm the disconnect is pushed in fully.

Float switches

Many Valley air handlers have a condensate float switch that kills cooling when a drain backs up. Look for a pan under the air handler and any recent water stains.

When to stop and get matched

Burning smells, grinding, repeated breaker trips, or ice on the coil — shut it down and request a match. Request help online.

General information only — not a diagnosis. LeadGrid Holdings LLC does not perform HVAC work.

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