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 Philadelphia, PA: 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 Philadelphia, PA

• 1
  Reliable Fire & Mechanical Inc. ★ Recommended

  Philadelphia, PA · 2155434558
• 2
  Jack Edmondson

  Philadelphia, PA · (215) 427-3228

We're still verifying other pros nearby before naming them.

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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.