AC Not Cooling But Fan Runs
Quick Answer
When your AC fan runs but doesn't cool, the most common causes are a dirty air filter, frozen evaporator coil, low refrigerant, or a failed compressor. Start by checking and replacing your air filter - this fixes the issue about 30% of the time.
Safe Checks You Can Do
- 1Check the air filter - A clogged filter restricts airflow and can cause the system to blow warm air. Replace if dirty.
- 2Inspect the outdoor unit - Make sure it's running and the fan is spinning. Clear any debris around it.
- 3Check thermostat settings - Ensure it's set to "cool" mode and the temperature is set below room temperature.
- 4Look for ice on the indoor coil - If you see frost or ice, turn off the AC and let it thaw for a few hours.
Likely Causes
- Dirty or clogged air filter
Restricts airflow, causing the evaporator coil to freeze or the system to work inefficiently.
- Low refrigerant (Freon leak)
Without enough refrigerant, the system can't absorb heat effectively. Requires professional repair.
- Frozen evaporator coil
Often caused by restricted airflow or low refrigerant. Ice blocks heat absorption.
- Failed compressor
The compressor pumps refrigerant. If it fails, the fan may still run but cooling stops.
- Dirty condenser coils
The outdoor unit can't release heat if the coils are covered in dirt and debris.
When to Call a Pro
- You've replaced the filter and the problem persists
- You see ice on the refrigerant lines or indoor coil
- The outdoor unit isn't running at all
- You hear unusual noises like clicking, buzzing, or grinding
- The system is more than 10 years old