10 Reasons Why Your AC Unit Isn’t Blowing Cool Air

image of a homeowner feeling hot and uncomfortable due to an ac unit not blowing cold air

AC systems play a vital role in maintaining a comfortable and healthy living environment during the hot summer weather. They regulate temperature and humidity. However, just like any other mechanical system, home cooling systems can experience problems, such as AC unit isn’t blowing cold air. When this happens, it is crucial to take action promptly to prevent discomfort, health hazards, and costly HVAC repairs. Understanding the importance of air conditioning systems and the implications of AC malfunctions can help you take proactive measures to ensure optimal performance and comfort.

Explore Our Home HVAC Services Call To Schedule A Free, In-Home Estimate

10 Reasons Why Your AC Unit Isn’t Blowing Cool Air

Here are a few pointers on what to check if your AC unit is not blowing cold air. Likewise, we also discuss how to resolve the problem quickly:

1. The Thermostat is Not Set Correctly

image of homeowner adjusting programmable thermostat

AC units only activate once the room’s temperature exceeds the control setting. So, make sure that your thermostat is set to “auto” and “cool” to ensure that it turns on when needed. The first thing you must do is confirm that the thermostat is adjusted to the correct temperature. Occasionally, the issue may arise if the thermostat is set to “heat” instead of “cool.”

If you recently had air conditioner service, there may have been an accidental adjustment. In such cases, switch the programmable thermostat to “heat” before setting it back to “cool.” Wait a few minutes. Then, check your registers to see if there is any cold air blowing through.

Call Today: (856) 665-4545

2. Dirty Air Filter

You need to check and replace your air filters regularly. If you don’t, they get severely clogged. When the filter is congested, it impedes airflow into your home. It can also damage the other components of the air conditioning unit, like the evaporator coil. Furthermore, you will notice that your HVAC system isn’t improving air quality as it should.

As a result, airborne particles will not be filtered out, and you may experience more dust and overall stuffiness, in addition to a lack of cold air. To prevent this, check your air filter every 30 days. Clean and replace it as necessary.

3. Dirty or Clogged Condenser

image of an air conditioner condenser

A dirty or clogged condenser coil may be causing your central air conditioner to produce warm air. The condenser fan pulls air through the condenser coil in the outdoor unit to extract the heat energy from your home during operation. However, the coil can become clogged with dirt, grass, and airborne particles obstructing airflow between fins. A dirty condenser unit causes a decrease in energy efficiency. It can even cause system failure or compressor damage due to overuse.

Remove dust and grime from the condenser coil. You can brush the debris away, vacuum the coil with a brush attachment, or gently rinse it with a hose. To effectively resolve this issue, contact a certified heating and cooling specialist.

Call For An Appointment Today: (856) 665-4545

4. Mechanical HVAC Problems

Like most things, cooling units undergo normal wear and tear over time. This means that mechanical problems may arise during the lifespan of the system. Understanding how your air conditioner functions can help identify potential mechanical issues from happening in the first place.

Make sure you check your thermostat and air filter. If your air conditioner is not functioning normally or not running as long as it should, contact your HVAC expert right away. Schedule an immediate inspection of your system’s internal components to make sure everything is in order.

5. Air Conditioner Refrigerant Leak

Air Conditioning Service By McAllister Energy

Another reason your central air conditioning system is not blowing cold air is a refrigerant leak. Refrigerants, such as R410a, are essential. This chemical coolant facilitates the production of cool air from the cooling unit. It travels through the indoor and outdoor coils of the system, transitioning from a liquid to a gaseous state. It also absorbs heat energy and humidity from the indoor air and expels it outside your home.

Refrigerant levels in the system do not typically decrease over time unless there is a leak in the refrigerant lines. When this happens, the system will not have enough coolant to generate cool air. It is important to note that attempting to repair refrigerant leaks on your own is not a good idea. Refrigerant is a chemical regulated by the EPA and can only be handled by certified experts. Your HVAC professional has the necessary tools to detect and repair refrigerant leaks. They can also replenish the coolant so your home can remain comfortable and cool.

Learn More About Our Home Cooling Services Call To Schedule An Appointment

6. HVAC Ductwork Leak

If there is a leak in the ductwork, the cold air will escape into the walls before it can reach the vents. This also implies that the same thing will happen to your heat during the winter.

Diagnosing a leak in the ductwork is hard. It will not just cost you the cold air you are paying for but also a lot of money on repairs. Contact your reliable HVAC professional for this issue.

7. Evaporator Coil Issues

air conditioner condensing coils

The evaporator coil is an indoor component of your air conditioning system. It eliminates heat energy and humidity from the air. When refrigerant levels in the system are low, the coils freeze, and frost can build up. This can lead to a lack of cold air production and higher energy expenses.

Accessing the evaporator coil is hard if you are not a professional. Leave this issue to an HVAC expert.

Call To Make An Appointment

8. Blocked HVAC Vents

An obstructed or blocked vent can have similar effects as a restricted or clogged air filter. The vents bring air into the HVAC system and distribute cold air to the entire house. Any blockage can pose a challenge to the air conditioning system.

If there is an obstruction near the vent, the room with the affected vent will feel warmer than other parts of the house. Call your trusted cooling technician right away to repair the issue.

9. Undersized Air Conditioning Unit

AC units are typically sized according to their BTUs, or cooling capacity. Unfortunately, undersized AC units do cause issues such as struggling to keep you cool as the outdoor temperature rises. This will cause your unit to work overtime, leading to an increase in wear and tear and, possibly, a premature replacement.

If you have an inadequate air conditioner, one option to consider is a ductless mini-split installation service. This can provide cooling to specific hot spots in your home. The best solution, however, is to replace your central air conditioner with an appropriately sized unit.


10. Lack of Regular Air Conditioner Maintenance

The best preventative measure to ensure your air conditioner cools your home effectively is scheduling an annual tune-up or maintenance service. Regular air conditioner maintenance will not only lower your energy bills but also detect current and potential problems.



It can be extremely aggravating when your air conditioning fails to function correctly, especially during the hot summer months. There are numerous reasons why your air conditioner is not performing well. It can range from simple issues like clogged filters and thermostat malfunctions to more complex problems like refrigerant leaks and compressor failures. Always make sure you hire a certified HVAC technician to diagnose and resolve the issue.

Get Started - Call McAllister Energy Today

Call McAllister Energy For All Of Your HVAC Requirements

McAllister Energy

McAllister Energy is the leading provider of heating and cooling services in Camden County, New Jersey. Our team consists of highly skilled and certified technicians who specialize in HVAC tune-ups, repairs, installations, and replacements. We take pride in delivering top-quality services to all our clients.

At McAllister Energy, we understand the importance of having a comfortable and energy-efficient home. That is why we offer competitive pricing for our services. Our maintenance services are designed to enhance your comfort and reduce your energy bills. If you require an HVAC repair or replacement, our knowledgeable technicians can recommend the best option while keeping your budget in mind. We stand behind our work and offer a satisfaction guarantee.

To schedule a service appointment with us, simply give us a call. We offer free, in-home estimates to help you make informed decisions about your HVAC systems. You can trust McAllister Energy to provide exceptional heating and cooling services that will exceed your expectations!

Call Now: (856) 665-4545 Read Our Reviews

You can click here to contact us now or call us at (856) 665-4545 to find out more! Click the link to view our service area.