Why is my AC running but not cooling?

Why is my AC running but not cooling

If you’ve ever experienced the frustration of your AC running but not cooling your home or office, you know how uncomfortable it can be. There are many reasons why your AC may not be functioning properly, but fortunately, there are also several troubleshooting steps you can take to pinpoint and resolve the issue.

Key Takeaways:

  • If your AC is running but not cooling, there may be an issue with the thermostat settings, air filter, condenser coils, refrigerant levels, fan or blower motor, vents, ductwork, outdoor unit, or the AC’s age and condition.
  • It’s important to troubleshoot the issue as soon as possible to prevent further damage and ensure your comfort.
  • If you’re unsure how to address the issue, it’s recommended to seek professional assistance or schedule regular maintenance for your AC.

Check the thermostat settings

If your AC is running but not cooling, the first thing to check is your thermostat settings. Incorrect settings can prevent your AC from cooling effectively. Make sure your thermostat is set to “cool” and the temperature is set lower than the current room temperature.

If your settings are correct, try adjusting the temperature by a few degrees. Wait a few minutes to see if the temperature changes. If it doesn’t, check the thermostat batteries or replace them if needed.

Checking and adjusting your thermostat settings is a simple and often overlooked troubleshooting step that may solve your AC cooling issue.

Clean or Replace the Air Filter

A dirty air filter can be a major cause of the AC not cooling properly. Over time, the air filter can become clogged with dirt, dust, and other debris, which restricts airflow and reduces cooling efficiency.

To check your air filter, locate the air intake register on your AC unit and remove the filter. Hold the filter up to the light to see if it appears dirty or clogged. If it does, it’s time to clean or replace it.

To clean the filter, use a soft-bristled brush or a vacuum cleaner to remove the accumulated dirt and dust. If the filter is beyond cleaning, purchase a replacement filter that matches the size and type of your current filter and install it according to the manufacturer’s instructions.

It’s recommended to clean or replace your air filter every 1-3 months to ensure proper airflow and cooling efficiency.

Remember, a dirty air filter can create more problems than just an inefficient AC system. It can also impact your indoor air quality, leading to respiratory problems, allergies, and other health issues.

By checking and maintaining your air filter, you can not only improve your AC performance but also ensure cleaner, healthier air in your home.

Inspect and clean the condenser coils

If your AC is still not cooling despite checking your thermostat and air filter, it’s time to inspect the condenser coils. The condenser coils are responsible for releasing hot air from your home, allowing your AC to cool the air more effectively. Dirty condenser coils can hinder this process, leading to decreased cooling performance.

To inspect the condenser coils, first, turn off the power to your AC. Then, locate the outdoor unit and remove any debris or plant growth surrounding it. Carefully remove the outer cover and visually inspect the coils for any dirt, dust, or debris. If you notice any buildup, it’s time to clean the coils.

Tools you’ll need: Steps to Clean the Condenser Coils:
– Vacuum Cleaner with Brush Attachment 1. Use the vacuum cleaner’s brush attachment to gently remove any visible debris from the coils.
2. Apply a coil cleaner according to the manufacturer’s instructions.
3. Allow the cleaner to sit for the recommended amount of time.
4. Rinse the coils thoroughly using a garden hose.
5. Reattach the outer cover and restore power to the unit.

It is crucial to handle the condenser coils with care as they are delicate and can be easily damaged. If you’re uncomfortable cleaning the coils yourself, or if you notice any signs of damage, it’s best to call a professional to properly clean or replace the coils.

By regularly inspecting and cleaning the condenser coils, you can improve your AC’s efficiency and extend its lifespan. With this simple task, your AC should be cooling your home in no time.

Check the Refrigerant Levels

If your AC is running but not cooling, low refrigerant levels may be the culprit. Refrigerant is the substance that cools the air within your AC system, so if it’s running low, your unit won’t be able to cool your home effectively.

To determine if low refrigerant is the problem, you can check the pressure levels in your AC unit. However, this should only be done by a trained professional, as handling refrigerant can be dangerous and requires specialized equipment.

If your AC is low on refrigerant, a professional HVAC technician can add more to the system. It’s important to note that low refrigerant levels are often caused by a leak in the system. Therefore, it’s crucial to have a professional find and fix any leaks before adding more refrigerant.

Ignoring low refrigerant levels can lead to decreased energy efficiency and increased wear and tear on your AC unit, eventually leading to more significant issues.

Examine the fan and blower motor

If the air filter and thermostat settings are in good condition, but your AC still isn’t cooling effectively, the issue may lie with the fan or blower motor. These components are responsible for circulating cool air throughout your home, and if they are malfunctioning, your AC won’t be able to do its job properly.

Start by examining the fan motor, which is usually located in the outdoor unit of your AC. Check for any visible damage or signs of wear and tear, such as frayed wires or loose connections. If everything looks good, you can try turning the fan by hand to see if it spins freely. If it doesn’t, this could be a sign that the motor is failing and needs to be replaced.

Next, move onto the blower motor, which is typically found in the indoor unit of your AC. Similar to the fan motor, check for any physical damage or loose connections. Turn the unit on and listen for any unusual sounds coming from the blower motor, such as grinding or squeaking. If you hear anything out of the ordinary, this could be a sign that the motor is failing and needs to be replaced.

If you are unsure about how to examine or replace the fan or blower motor, it’s best to consult with a professional HVAC technician who can quickly and accurately identify and fix the issue. Neglecting fan or blower motor problems can lead to further damage to your AC and ultimately result in costly repairs or replacements.

Check for blocked or closed vents

If your AC is running but not cooling, it could be due to blocked or closed vents. Airflow is essential for proper cooling, and any obstruction can impede the process.

Start by checking all the supply and return vents in your home. Ensure they are open and unobstructed by any furniture, rugs, or decor. If they are dirty, clean them with a damp cloth or vacuum.

If you have closed any vents in unused rooms, open them to allow proper airflow throughout your home. Closed vents can cause pressure imbalances, reducing the effectiveness of your AC.

Avoid blocking vents with any items, such as curtains, as this can restrict airflow. Always keep them free and clear to allow proper circulation of air.

If you have pets, they may shed fur and dander that can collect in your vents, causing blockages. Regular cleaning can help prevent this issue.

Checking and addressing any blocked or closed vents can significantly improve your AC’s cooling efficiency and ensure comfortable temperatures in your home.

Inspect the ductwork for leaks or damage

If your AC is running but not cooling, the issue may be caused by leaky or damaged ductwork. Air leakage in the ductwork can cause the cool air to escape before it reaches your living space, leading to poor cooling performance. Verify that all air registers and grilles are wide open and unobstructed by furniture, carpets, or other objects.

To check for duct leaks, you can conduct a visual inspection by looking for any visible holes, gaps, or tears in the ductwork. You can also conduct a simple test by feeling if any air is leaking out of the ducts. Use a smoke pencil or an incense stick to trace and pinpoint any leaks.

If you detect any leaks, patch them up using duct tape or mastic sealant. If you find any damaged or collapsed ducts, consider replacing them to ensure that your AC system operates at maximum efficiency. Repairing leaky or damaged ductwork can improve your cooling performance and help reduce your energy costs.

Check the outdoor unit for obstructions

If your AC is running but not cooling, the outdoor unit may be the culprit. Obstructions obstructing the unit can reduce airflow and affect the cooling process. Here’s how you can check for obstructions:

  1. Start by turning off the power to the unit.
  2. Inspect the area immediately surrounding the outdoor unit. Clear away any debris, such as sticks, leaves, or grass clippings.
  3. Trim back any bushes or vegetation that may be encroaching on the unit.
  4. Check for any objects, such as furniture, that may be blocking the unit’s air intake or exhaust vents.
  5. Ensure that the unit has adequate clearance on all sides to allow for proper airflow. Refer to your manufacturer’s guidelines for specific clearance requirements.

If you spot any obstructions, remove them carefully to avoid damaging the unit. Once you’ve cleared away any potential obstructions, turn the power back on and see if your AC’s cooling performance has improved.

Schedule professional maintenance

If your AC is still not cooling despite troubleshooting, it may be time to schedule professional maintenance. A professional technician can identify and address any underlying issues that may be preventing your AC from cooling properly. Additionally, regular maintenance can help prevent future problems and prolong the life of your AC.

Professional maintenance may include tasks such as checking refrigerant levels, inspecting and cleaning the condenser coils, tightening electrical connections, and lubricating moving parts. It’s important to choose a reputable and experienced HVAC company to ensure that the maintenance is done correctly and efficiently.

Keep in mind that regular maintenance can also help you save money in the long run by improving the efficiency of your AC and reducing energy costs. So don’t wait until your AC breaks down completely, schedule professional maintenance today and enjoy a comfortable and cool home all summer long.

Remember, when it comes to professional maintenance, you don’t have to do much except make the call and schedule an appointment. Leave the hard work to the experts and relax knowing that your AC is in good hands.

Consider the age and condition of your AC

If you have tried all the troubleshooting steps and your AC still isn’t cooling, it may be time to consider the age and condition of your unit.

Air conditioners typically last around 10-15 years, depending on usage and maintenance. If your AC is approaching or exceeding that age range, it may be time to start thinking about a replacement.

Additionally, if your AC has been experiencing issues for a while, it may have sustained damage that is beyond repair. In these cases, investing in a new unit may be more cost-effective in the long run.

It’s important to consult with professionals to determine whether a replacement is necessary, and they can also advise you on the best options for your specific situation.


Congratulations, you have successfully troubleshooted your AC cooling issue! By following the steps outlined in this article, you have likely resolved the problem and restored your AC’s cooling efficiency. Remember to regularly clean or replace your air filter, inspect and clean your condenser coils, and check for any obstructions in your vents or outdoor unit to prevent future cooling issues.

If you have tried all the troubleshooting steps and your AC is still not functioning properly, don’t hesitate to seek professional assistance. A licensed HVAC technician can diagnose and resolve any complex issues or recommend if it’s time to replace your aging or damaged AC unit.

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