Air Conditioner Does Not Blow Cold Air
If your air conditioner is running but not blowing cold air, the problem could be caused by a dirty air filter, low refrigerant, a faulty compressor, or a malfunctioning thermostat. Before replacing any parts, inspect the most common causes listed below.
Safety Notice: Always turn off power to the air conditioner before servicing it. If you notice electrical issues, unusual noises, or refrigerant leaks, disconnect power immediately and have the system inspected before operating it again.
Possible Causes
- Dirty or clogged air filter
- Low refrigerant level
- Dirty condenser coils
- Faulty thermostat
- Failed compressor
- Defective condenser fan motor
- Frozen evaporator coil
- Failed capacitor
1. Dirty or Clogged Air Filter
Most Common Solution
A dirty air filter restricts airflow across the evaporator coil, reducing the system's ability to cool your home efficiently. In severe cases, restricted airflow can also cause the evaporator coil to freeze.
What to do:
- Turn off the air conditioner.
- Remove and inspect the air filter.
- Replace the filter if it is dirty or clogged.
- Restore power and check if cooling improves.
2. Low Refrigerant Level
Low refrigerant reduces the system's cooling capacity and is commonly caused by a refrigerant leak.
What to do:
- Look for ice buildup on the refrigerant lines or evaporator coil.
- Inspect for signs of an oily residue near refrigerant connections.
- Have the leak repaired before recharging the refrigerant.
3. Dirty Condenser Coils
Condenser coils release heat from the refrigerant. When they become dirty, the air conditioner cannot efficiently remove heat, reducing cooling performance.
What to do:
- Turn off power to the outdoor unit.
- Remove leaves, grass, and debris from around the condenser.
- Carefully clean the condenser coils using a coil cleaner or gentle stream of water.
4. Thermostat
An incorrectly set or malfunctioning thermostat can prevent the air conditioner from cooling properly.
What to do:
- Verify the thermostat is set to Cool mode.
- Set the temperature below the current room temperature.
- Replace the thermostat batteries if applicable.
- Replace the thermostat if it is defective.
5. Compressor
The compressor circulates refrigerant through the cooling system. If it fails, the air conditioner may run but produce little or no cold air.
What to do:
- Listen for the compressor while the outdoor unit is operating.
- Check for unusual humming or clicking sounds.
- Replace the compressor if it has failed.
6. Condenser Fan Motor
The condenser fan motor removes heat from the outdoor condenser coil. If the fan fails, cooling performance drops significantly.
What to do:
- Inspect the outdoor fan while the unit is running.
- Verify the fan blades spin freely.
- Replace the fan motor if it is defective.
7. Frozen Evaporator Coil
A frozen evaporator coil blocks proper heat transfer and greatly reduces cooling performance.
What to do:
- Turn off the air conditioner.
- Allow the evaporator coil to thaw completely.
- Replace the air filter if necessary.
- Inspect for airflow restrictions or low refrigerant if the problem returns.
8. Capacitor
The compressor and fan motors rely on capacitors to start and run properly. A failed capacitor can prevent one or both motors from operating correctly.
What to do:
- Disconnect power to the air conditioner.
- Inspect the capacitor for bulging, leaking, or corrosion.
- Test the capacitor using the proper equipment.
- Replace it if it is defective.
Need Help Finding the Correct Part?
If you need help identifying the correct replacement part, send us your complete air conditioner model number and a clear photo of the appliance identification label before placing your order. Our team will verify compatibility and help ensure you receive the correct replacement part the first time.