Why Is My AC Not Cooling? 7 Common Causes

When your air conditioner is running but not cooling your home effectively, it can be frustrating and uncomfortable. Here are the seven most common causes and what you can do about them.

1. Dirty Air Filter

A clogged air filter restricts airflow, reducing your AC's cooling capacity. Check and replace your filter every 1-3 months, especially during peak cooling season.

2. Low Refrigerant

If your system is low on refrigerant, it won't cool effectively. This usually indicates a leak that needs professional repair.

3. Frozen Evaporator Coil

Poor airflow or low refrigerant can cause the evaporator coil to freeze. Turn off your AC and let it thaw, then call a professional if the problem persists.

4. Dirty Condenser Coils

The outdoor unit's condenser coils can become covered in dirt and debris, reducing efficiency. Regular cleaning helps maintain performance.

5. Faulty Thermostat

If your thermostat isn't reading temperature correctly or isn't communicating with your AC, cooling will be inconsistent.

6. Compressor Issues

The compressor is the heart of your AC system. If it's failing, you'll need professional diagnosis and repair.

7. Ductwork Leaks

Leaky ducts can lose up to 30% of cooled air before it reaches your rooms. Professional duct sealing can significantly improve cooling.

When to Call a Professional

While you can handle filter changes and basic cleaning, most AC issues require professional diagnosis and repair. If your AC isn't cooling properly, book a service call to prevent further damage and restore comfort.