AC Not Blowing Cold Air Troubleshooting

A properly working air conditioner is a must-have for every home, especially during this summer heat. Without that nice, cool air, you and your family can easily get overheated and uncomfortable. However, just like any other device, air conditioners can malfunction.

Many potential air conditioning issues may come up, and one of the most frustrating is when the system stops blowing cold air. This unfortunate problem can occur for a variety of reasons. Sometimes, it’s due to a part malfunctioning, breaking, or wearing out. Other times, it can happen simply because you haven’t stayed on top of AC maintenance. 

Luckily, there are several troubleshooting methods you can try to get your cooling system back on track. With my HVAC expertise, I will cover a few of the most likely reasons your AC not blowing cold air and how to fix them. 

Let’s get started! 

Bottom LineUp Front

If your air conditioner isn’t blowing cold air, the problem may be as simple as a filthy air filter. Before hiring experienced technicians and investing money, it’s always worth attempting some basic troubleshooting. Your air conditioner filter captures dust, grime, and other impurities before they enter the system. That filter will eventually get very dirty — if not clogged.

A clogged air filter might restrict the device’s airflow, preventing it from regularly delivering cold air. So, if your cooling system is experiencing this issue, it’s usually a good idea to start by replacing the air filter. If that doesn’t work, you can continue on to other possible remedies.

Why Is Your AC Not Blowing Cold Air?

A household air conditioner failing to blow cold air is very common. The cooling process involves many parts working together, which means there are many possible causes of the issue. Sometimes, it’s happening because something is restricting the system’s airflow.

In other cases, it could be that the appliance is having trouble removing heat energy from the air. It’s also possible that one or more components are simply not working, preventing the AC unit from doing its job.

How Does the Cooling Process Work?

The process your air conditioner uses to cool down your home features several steps and many different parts.

• The vent pulls warm air from the house and blows it over the cold evaporator coil.
• The evaporator coil removes the heat from the air to reduce its temperature.
• The refrigerant is converted from a liquid to a gas as it absorbs heat
• The fan blows the cold air through the ducts and around the house
• The refrigerant gas reaches the condenser and expels the heat outside the house
• The refrigerant is converted back to a liquid as it loses its heat
• The cold refrigerant travels back to the evaporator coil to start the cooling process over again

How to Troubleshoot Your AC Not Blowing Cold Air

Here, we’ll look closely at some of your AC unit’s problems. Every situation is different, but these are usually the most common reasons a cooling system will struggle to blow cold air.

Possibility 1: Thermostat Set Incorrectly

Sometimes, the most straightforward answer is the correct one. Whether or not your air conditioner is blowing cold air depends on how your household thermostat is set.

The system will know to blow cool air if it is set at a temperature lower than the current home climate. However, if the thermostat isn’t set correctly, your HVAC system may be blowing warm air when it should be blowing cold air.

How to Fix

• Check your household thermostat to see what temperature it’s set to
• If it’s set to a warmer temperature than you want, manually adjust its setting
• Wait a few minutes to see if the AC begins blowing cold air
• If this doesn’t solve the problem, you may need to replace your thermostat or have it recalibrated by HVAC professionals

Possibility 2: Leaking Refrigerant

Refrigerant is extremely important for your air conditioner to cool down the air in your home. If the system doesn’t have enough of this chemical, it won’t be able to remove the heat energy from the air effectively.

As a result, the AC unit will likely still be running, but the air temperature may be inconsistent or unusually warm. Sometimes, a cooling system may develop a refrigerant leak, making it impossible for the unit to do its job correctly.

How to Fix

• If your AC unit regularly blows warm air, it may have a refrigerant leak somewhere.
• Check around the indoor and outdoor unit for any signs of a leak.
• Not all refrigerant leaks are visible or easy to find, but that doesn’t mean they aren’t there.
• If your air conditioner leaks refrigerant, you’ll need to hire professional technicians to seal it.
• Once the leak has been repaired and the missing refrigerant replaced, the system should be back to blowing cold air.

Possibility 3: Blocked Condenser Unit

The condenser coil is an essential component of your air conditioning system. The coil, wrapped around the outdoor unit, features a series of metal fins. Over time, things like leaves, dirt, and random debris can build up around the outdoor unit.

In some cases, those objects can get stuck between the metal fins of the condenser coil. When that happens, it can clog up the condenser unit and restrict your cooling system’s airflow. That can negatively affect the system’s ability to blow cold air consistently.

How to Fix

• Check your air conditioner’s outdoor condenser unit to see if it’s dirty or blocked.
• If the condenser coil is blocked, you can either scrub between the fins with a brush or gently rinse it off with a hose.
• Wait a few minutes to see if the AC unit starts blowing cold air
• To avoid this problem in the future, make sure to check and clean your system’s outdoor condenser unit regularly

Possibility 4: Frozen Evaporator Coil

Your air conditioner’s indoor unit contains an evaporator coil, which is very important for removing heat from the air. If this coil becomes frozen, it will affect the system’s ability to blow air around the house.

Usually, when the evaporator coil freezes, something stops the air conditioner from having consistent airflow. Fortunately, there are several clear signs you can look for to figure out whether or not your AC’s evaporator coil is frozen.

How to Fix

• The evaporator coil will be in its unique cabinet if you have a furnace.
• The evaporator coil will be in the fan coil cabinet if you have a heat pump.
• Look for any frost on the copper tubing from the evaporator coil’s cabinet.
• Check for any signs of water leaking out of your air conditioner’s indoor unit.
• If you see any signs that the evaporator coil is frozen, you should shut off your AC and schedule an appointment with HVAC professionals.
• Technicians will figure out why the coil has become frozen and find a fix for the problem.

Possibility 5: Ductwork Leak

Sometimes, an air conditioner will fail to blow cold air because of leaky ductwork. When your AC unit is running, it’s constantly blowing air through the ducts to reach the different areas of the house.

However, some of that air may escape if there are any gaps, cracks, or other openings in the ducts. If a lot of the cold air is leaking out from the ducts, it will never reach the rooms of your house. 

How to Fix

• Your ductwork should be cleaned and inspected every two or three years.
• If you notice that some areas of the house are getting more cold air than others, it could be due to leaky air ducts.
• When you think your ductwork may have leaks, you should schedule an appointment with ductwork professionals.
• Air duct experts can clean the contaminants from your ductwork and check for any leaks or other damage.
• If they find any leaks, they’ll be able to repair them to fix the issue promptly.
• After having your ductwork cleaned, your HVAC system will be healthier and more energy-efficient

Possibility 6: Undersized Air Conditioner

Another possible reason for the AC problem could be that your air conditioner is too small for your home. Under normal conditions, you may not notice if your AC unit is too small. However, as the temperature outside gets hotter, the system may have trouble cooling your home effectively.

If you have a large house, you need an AC unit that is powerful enough to cool all its rooms. If the appliance is undersized, you may notice that it cannot consistently blow cold air to specific areas.

How to Fix

• If it seems like some parts of your home are getting more cold air than others, your AC unit may be too small.
• You can schedule an appointment for local HVAC professionals to inspect your household situation.
• AC experts will be able to examine your home and air conditioner to determine if it’s the right size or not.
• If it turns out that your air conditioner is too small, you may need to upgrade to a more robust system.

Possibility 7: Broken or Malfunctioning Component

If none of the above problems are why your AC unit isn’t blowing cold air, there may be a broken or malfunctioning part in the system. It’s possible that the fan, compressor, or some other part is not properly doing its job.

Sometimes, all it takes is one component having trouble completely messing up the cooling process.

How to Fix

• If you’ve ruled out the other possibilities, it could be a malfunctioning or broken part preventing your AC from blowing cold air.
• Instead of diagnosing the problem alone, you should leave it to trained professionals.
• Schedule an appointment with local AC technicians and let them thoroughly inspect your air conditioner.
• The professionals should be able to figure out which part is causing the problem and find an effective fix.

Frequently Asked Questions

Final Takeaway

It’s always frustrating when your air conditioner isn’t blowing cold air. After all, nobody likes being stuck in a hot, uncomfortable house in the middle of summer. However, it doesn’t necessarily have to be a disaster. Before panicking, it’s always smart to try simple troubleshooting methods first. There’s a good chance that one of those essential solutions will either solve or improve your AC problem.

Even if those troubleshooting methods don’t get the job done, the issue may not be a big deal. If you call up your trusted local HVAC professionals, they will most likely be able to diagnose the problem quickly. Then, the solution may be relatively quick and painless for you and your family. What’s important is that you take things one step at a time and pay attention to what your air conditioner is telling you.

When your air conditioner stops blowing cold air, your first step should be to address the most basic troubleshooting methods. First, double-check the thermostat settings. Check to see whether the thermostat hasn’t been mistakenly set to a higher temperature than you prefer. If it has, it should be a simple remedy to get your air conditioner running again.

If the thermostat is not the issue, you should replace the air filter in your air conditioner. If the filter is dirty or blocked, you should replace it with a new one. There’s a strong possibility you’ll be able to solve your problem fast and easily. If these solutions don’t work, it’s time to start looking for other potential problems and using the different troubleshooting techniques I addressed in this article.  

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Emmanuel Joseph

Emmanuel found himself interested in the HVAC industry because he was curious about how the weather and environment affect our overall comfort and the solutions we use to stay comfortable in our homes. He knows it can be difficult to keep your own home comfortable year-round, and a lot goes into maintaining an HVAC system to keep it running perfectly. He gives you all of that information, and more so you can relax comfortably in your home regardless of the weather outside.

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