AC blowing warm air — San Francisco, California
When your air conditioner runs but only blows warm or room-temperature air, the most common culprits are a dirty air filter restricting airflow, low refrigerant from a leak, a frozen evaporator coil, a failed compressor, or an incorrect thermostat setting. A clogged filter is the easiest DIY fix — replace it and wait 3–4 hours for a frozen coil to thaw. If the problem persists, the system likely has a refrigerant leak or a component failure that requires a certified HVAC technician. Refrigerant leaks require EPA-certified handling, and recharging without fixing the leak is both illegal and wasteful. Diagnosis costs $75–$200; common repairs range from $150 (capacitor) to $1,500+ (compressor replacement).
Why this is common in San Francisco
The cool, foggy maritime climate means central AC is rare and rarely needed, so HVAC work centers on heating efficiency, ventilation, and increasingly heat-pump retrofits driven by Title 24 energy rules. Older homes often have undersized or outdated heating systems requiring careful upgrades.
Who to call
For this problem in San Francisco, call a: HVAC Technician
Find a HVAC Technician in San FranciscoSymptoms to look for
- Air from vents feels warm or the same temperature as the room
- AC unit runs continuously but the house never reaches the set temperature
- Ice buildup visible on the outdoor unit or refrigerant lines
- Higher than normal electricity bills without increased usage
Emergency Service in San Francisco
Emergency home services in San Francisco are available 24/7 at premium rates — expect $150–$300+/hour for after-hours plumbing or electrical, the highest tier in the US. Response times average 45–90 minutes given hilly terrain and parking scarcity. Always verify an active CSLB license and proper DBI permits.