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 San Diego, 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 San Diego, CA
- Legacy Plumbing Heating & Air · 2534 State St Ste 457, San Diego, CA · 6194530365
- HVAC NOW California · 550 W Date St Ste 312, San Diego, CA · (619) 333-6356
- Ray Williams Refrigeration & Air Conditioning Inc. · 737 17th St, San Diego, CA · +16192333388
- SAN DIEGO MECHANICAL PRO · 415 LAUREL STREET 427, SAN DIEGO, CA · (858) 376 7506
- ROBERTSON MECHANICAL INC · P O BOX 7098, SAN DIEGO, CA · (619) 840 9191
- Carini Home Services · 825 Washington St, San Diego, CA · 6193325176
- San Diego Heating & Air Conditioning · 1286 University Ave 279, San Diego, CA · 6192724221
- Big City HVAC and Appliance Repair · 3113 Market St # A, San Diego, CA · +16195418118
Get free quotes from San Diego, 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.