Your AC Stopped Cooling: 6 Things to Check Before You Panic

It's the hottest week of the year — that's always when it happens — and the vents are blowing warm. Before you assume the compressor is dead, spend ten minutes on these checks. A surprising number of "broken" air conditioners are fixed by step three.

1. Check the thermostat first

Make sure it's set to COOL, not just ON (fan mode blows air without cooling it). If the screen is blank, replace the batteries. If someone in the house "adjusted" it, you may just be in a schedule or hold mode.

2. Look at the air filter

A clogged filter chokes airflow so badly the system can freeze itself into a block of ice and stop cooling entirely. If you can't remember the last time you changed it, that might be your answer. Filters should be changed every 1–3 months.

3. Check the breaker panel

AC systems usually have two breakers — one for the indoor unit, one for the outdoor condenser. A tripped outdoor breaker means the fan inside runs (so it feels like the AC is "on") while no cooling happens outside. Flip a tripped breaker fully OFF, then back ON.

4. Look at the outdoor unit

Is the big fan on top spinning? Is the unit caked with cottonwood fluff, leaves, or grass clippings? A condenser needs to breathe — gently rinse the fins with a hose (power off first) if they're matted over.

5. Check for ice

Ice on the copper lines or the indoor coil means the system froze — usually from that dirty filter or low refrigerant. Turn the system OFF and run only the fan for a few hours to thaw it before any technician can even diagnose it.

6. Check the drain line

Many systems have a safety switch that shuts everything down when the condensate drain clogs. If you see a small PVC pipe near the indoor unit and a pan with standing water, that switch may have tripped.

When it's genuinely broken

If none of that brings the cold back, you're likely looking at a refrigerant leak, a failed capacitor or motor, or a compressor problem — real repairs that need a licensed technician. This is the moment a home warranty changes everything: instead of cold-calling contractors in peak season and taking whatever price the emergency market bears, you file one claim, pay one flat service fee, and a licensed pro handles it.