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 Francisco, 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 Francisco, CA
- CLADDAGH REFRIGERATION COMPANY INC · 1434 15TH STREET, SAN FRANCISCO, CA · (415) 643 9248
- IY DEVELOPMENT & RENOVATION INC · 95 THIRD ST 2ND FLOOR, SAN FRANCISCO, CA · (833) 288 8008
- Wolff Olins · 972 Mission St Fl 2, San Francisco, CA · +14159016410
- Next HVAC and Appliance repair · 1 Henry Adams St Unit S324, San Francisco, CA · 4156550218
- SwiftBreeze HVAC Solutions · 131 Hayes St, San Francisco, CA · +14159306101
- HVAC & Heating Systems Installation San Francisco · 1182 Market St #425, San Francisco, CA · +15103594177
- Genhome Hvac · 222 Mason St, San Francisco, CA · +14158348700
- Rich Air Duct Cleaning · 2261 Market St, San Francisco, CA · +14156870015
Get free quotes from San Francisco, 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.