Why is my AC running but not cooling?

An AC that runs without cooling is most often a dirty filter choking airflow, a failed capacitor, or low refrigerant from a leak. The filter you can fix in two minutes; a frozen coil means shut it off and let it thaw before a tech comes, or the real problem can't be diagnosed.

Likely causes

• Clogged filter — Starved airflow freezes the coil and kills cooling — check this first, always.
• Failed capacitor — The outdoor fan or compressor won't start properly; a common, relatively cheap repair.
• Refrigerant leak — Ice on the refrigerant lines plus weak cooling. Refilling without fixing the leak buys weeks, not years.
• Dirty outdoor condenser — Cottonwood, grass, and debris insulate the coil so heat can't escape.

What you can check yourself

• Replace the filter. If the indoor coil is iced, turn the system off (fan on) for 3–4 hours to thaw.
• Clear debris from around the outdoor unit — 2 feet of clearance on all sides.
• Check that the thermostat is on 'cool' and below room temperature (it happens more than anyone admits).

Typical cost

Typical repairs in Los Angeles, CA: capacitor $150–$350; refrigerant leak repair + refill $450–$1,200; fan motor $300–$600.

When to call a pro

Ice keeps returning, the breaker trips, or it blows warm after a filter change and thaw — those need a tech, and running it meanwhile can kill the compressor.

HVAC pros in Los Angeles, CA

• Accelerate Heating & Ac Repair · 333 S Figueroa St, Los Angeles, CA · 14242735345
• Complete Energy And Air · 453 S Spring St Ste 400, Los Angeles, CA · +13106955814
• Los Angeles Heating and Air Conditioning · 114 San Pedro St, Los Angeles, CA · +12136953895
• Alaric HVAC AC Service Loss Angeless · 707 N Broadway, Los Angeles, CA · +12134744475
• Los Angeles HVAC Repair Service · 1005 W Rondout St, Los Angeles, CA · +12133761525
• Southwest Heating & Air Conditioning · 622 Alpine St, Los Angeles, CA · +13108670703
• Delux AC Repair Los Angeles · 820 S Grand Ave, Los Angeles, CA · +14243095123
• Bgreenla · 1055 Wilshire Blvd Ste 1475, Los Angeles, CA · (213) 353-3982

Get free quotes from Los Angeles, CA pros →

Data by Servik — verified local pros from official license records and public sources. Cost figures are typical ranges, not quotes; a pro's written estimate is the real number.