An air conditioner running but not cooling is commonly caused by dirty filters, thermostat issues, refrigerant leaks, dirty coils, fan issues, leaky ductwork, or an aged system. You can fix it by replacing the filters, adjusting the thermostat, inspecting the outdoor unit, and much more.
It can go from minor issues you can fix yourself to more complex problems requiring professional help. Understanding why your AC is blowing but not cooling and knowing some basic troubleshooting steps can help restore your comfort quickly. Read to discover!
Why Is My AC Not Cooling?
It can be frustrating when your air compressor is running but not cooling, especially during the hottest months. There are several reasons why an air conditioner might be running without effectively cooling the air, and the most common causes are:
- dirty air filter;
- thermostat issues;
- refrigerant leak;
- dirty coils;
- fan or blower issues;
- leaky ductwork; and
- aged or overworked system.
Now that you know what could be causing your AC to be running but not cooling the house, read the following section to understand what you can do about it.
How To Fix An AC Unit Not Cooling? 8 Basic Steps
Once you identify the possible cause, you can start AC troubleshooting to try to solve the problem. Checking the filters, adjusting the thermostat, checking for refrigerant leaks, and inspecting the outdoor unit are just some of the possible solutions. Read on!
1. Check And Replace The Air Filter
A clogged or dirty air filter restricts airflow, causing the AC unit to work harder and reducing its cooling efficiency. A dirty air filter is one of the most uncomplicated issues to fix. Inspect the filter and replace it if it appears clogged.
2. Adjust The Thermostat
If your thermostat is not set correctly or is malfunctioning, it could cause the AC unit to run without cooling even or adequately and the AC not turning on. Ensure that the thermostat is set to "cool" at the desired temperature. If you have a programmable thermostat, check the schedule to make sure it is working correctly.
3. Check For Refrigerant Leaks
Refrigerant is essential for cooling, and a leak in the system can result in a low refrigerant level, causing the AC to run but not cool the air. Low refrigerant often requires a professional to inspect for leaks, recharge the system, and guarantee proper pressure. Attempting to add refrigerant yourself is not advised, as it requires specialized equipment and knowledge.
4. Inspect The Outdoor Unit
If the coils are dirty, your AC cannot efficiently release heat outside, making it difficult to cool the air. It will lead to an AC turning on and off frequently or one that cannot actually cool the room. Clear any dirt, debris, or leaves from the outdoor condenser coils. You can gently rinse the coils with a hose to remove any buildup.
5. Clean The Evaporator Coils
If the evaporator coils are dirty, you may need to remove the filter and use a soft brush or vacuum cleaner to carefully remove dust and debris. However, for more thorough cleaning, professional assistance is recommended.
6. Examine The Fans And Blower Motor
Look for any visible obstructions or debris around the fan blades in the outdoor unit and clear it if necessary. For internal fans or motors, if there are strange noises or a lack of airflow, it may require a professional inspection.
7. Check Ductwork
For central AC systems, damaged or leaking ductwork can cause cool air to escape before it reaches your rooms. It results in an AC unit that runs longer without making the air cooler.
Inspect exposed ductwork for any visible holes or tears. While minor leaks can be sealed with foil tape or mastic, an HVAC professional should do larger ductwork repairs.
8. Schedule Professional Maintenance
If your AC continues to run without cooling, it may be due to a more complex issue or aging components. Regular professional maintenance, which includes cleaning and system checks, can help prevent recurring problems and keep your system running efficiently.
If your AC is running but not cooling even after you have tried the steps above, contact a qualified HVAC technician. Professionals can diagnose the underlying issue and provide necessary repairs with more efficiency.
