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Heating and air · checked 5 Oct 2026

The AC is running but not cooling

Safety first

  1. Move everyone somewhere air-conditioned if the house is getting dangerously hot.
  2. Confusion or collapse in heat: call 911; cool with wet cloths.
  3. Check for visible ice; if present, turn cooling OFF.

Fix it nowEight steps

  1. Look for exposed-line ice; if present, turn cooling OFF and call HVAC.Stop these checks; let ice melt naturally, without tools or heat.
  2. Turn thermostat OFF; set fan AUTO; wait until the blower stops.Stop airflow before handling an accessible filter.
  3. Replace dirty return-grille filters with matching size/type; point airflow arrows toward duct.Restore airflow; skip filters requiring equipment covers or unsafe access.
The other five steps
  1. Open supply vents; move furniture away from vents and return grilles.Blocked airflow can reduce cooling and cause freezing.
  2. Set thermostat COOL, fan AUTO, and temperature two degrees below room temperature.Make sure the thermostat actually requests cooling.
  3. Wait 15 minutes; check whether supply air becomes noticeably cooler.Allow startup delays; avoid repeatedly switching the system.
  4. If air stays warm, turn cooling OFF and call an HVAC professional.Refrigerant and electrical repairs require a trained technician.
  5. Relocate to air-conditioning if indoor heat rises; prioritize children and vulnerable adults.Children, older adults, and medically vulnerable people face greater heat risk.

When to stop

Stop and get a heating and air technician if:

  • Ice appears or returns: turn cooling OFF; call an HVAC professional.
  • Water leaks around the indoor equipment: stop using it; call HVAC.
  • A breaker trips: stop troubleshooting; do not repeatedly reset it. Call HVAC.
  • Air stays warm after these checks: turn cooling OFF; call HVAC.
  • Someone becomes confused, collapses, or has slurred speech in heat: call 911; cool with wet cloths.

What it probably is

Incorrect thermostat settingsCOOL is not selected, or the setpoint exceeds room temperature.You can check
Restricted airflowThe filter is visibly clogged, or furniture blocks vents or returns.You can check
Frozen indoor coilIce appears on exposed refrigerant lines; airflow may weaken.For a pro
Refrigerant leakCooling stays poor despite correct settings and a clean filter; ice may appear.For a pro
Compressor or electrical-control failureIndoor air blows, but outdoor equipment stays silent during a cooling call.For a pro

Time and parts

Time
Estimated 20–30 minutes for basic checks. Ice can take several hours to thaw.
Parts
$0–$30 for no parts or a typical disposable filter; specialty filters cost more.

Get it done

More than a quick fix? Vora gets quotes privately and recommends one heating and air technician.

Ask Vora about this

Checked against

  1. Carrier: Will Frozen AC Fix Itself?
  2. Carrier: All About AC Filters
  3. CDC: Heat-related Illnesses

Written for Vora from these public sources and checked on 5 Oct 2026. General guidance, not a substitute for a pro on site. In danger, leave and call 911.

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