When Your AC Freezes Up: Causes and Solutions

An air conditioner that freezes up is a common issue many homeowners and business owners encounter, especially during the peak of summer heat in Texas and Oklahoma. While air conditioners are designed to cool your home by circulating cold air, a frozen unit will struggle to do its job, leading to inefficient performance and potentially causing significant damage if not addressed promptly. If your AC has frozen up, it’s important to understand the possible causes and solutions so that you can restore comfort to your indoor environment quickly and avoid unnecessary repair costs.

Why Does Your Air Conditioner Freeze Up?

Several factors can contribute to an air conditioning unit freezing up, all of which are important to identify and address before the situation worsens. Below are the most common causes of frozen AC units:

1. Low Refrigerant Levels

Refrigerant is the substance that absorbs and expels heat to cool the air. If your AC unit is low on refrigerant—due to a leak or improper charging—this will disrupt the cooling cycle. Low refrigerant levels cause the evaporator coils to get too cold, leading to condensation on the coils that can freeze. This ice buildup not only limits your system’s ability to cool but can also cause damage to the compressor, a vital component of your air conditioner.

Solution: If low refrigerant is the problem, a licensed HVAC technician will need to locate and repair the leak, then recharge the system with the appropriate amount of refrigerant. Attempting to fix a refrigerant leak without professional help is illegal in many places, as improper handling of refrigerants can be harmful to the environment.

2. Dirty Air Filters

Air filters are responsible for trapping dust, dirt, and other debris to keep the air clean and protect the system. When the air filters become clogged, airflow to the evaporator coils is restricted. Without proper airflow, the coils can’t absorb heat efficiently, causing the temperature to drop too low and the moisture in the air to freeze on the coils.

Solution: Regularly check and replace the air filters in your system to ensure optimal airflow. In most cases, filters should be replaced every 1-3 months, depending on usage and the environment. If you’ve noticed ice buildup, changing the filter is one of the first steps to solving the issue.

3. Blocked or Dirty Evaporator Coils

Over time, the evaporator coils can accumulate dirt and dust, especially if the air filter has not been changed regularly. When the coils are dirty, they struggle to absorb heat effectively, which can cause the temperature of the coils to drop too low and freeze any moisture present on the coils.

Solution: If you suspect dirty coils, it’s best to have a professional HVAC technician clean them thoroughly. Coils should be inspected and cleaned regularly as part of routine air conditioning maintenance to ensure your system runs efficiently.

4. Poor Airflow Due to Duct Issues

Ductwork plays an essential role in distributing cooled air throughout your home or business. If your ducts are leaky, blocked, or poorly insulated, airflow to the evaporator coils can be reduced. This can lead to a drop in temperature, which in turn causes the coils to freeze. Airflow issues can also be the result of closed or blocked vents.

Solution: Have your ductwork inspected for leaks, blockages, or other issues that may be restricting airflow. Ensure that all supply vents are open and unobstructed. In some cases, the installation of additional insulation or the sealing of leaks may be necessary to improve airflow.

5. Thermostat Problems

If your thermostat is malfunctioning or not properly calibrated, it may cause the AC unit to run longer than needed, which can result in the evaporator coils getting too cold. Additionally, a faulty thermostat might fail to signal the system to cycle off when it should, causing it to run constantly and freeze up.

Solution: Have your thermostat checked by a professional to ensure that it’s accurately reading the temperature and signaling the air conditioner to operate correctly. If your thermostat is outdated or damaged, it may need to be replaced to prevent future issues.

6. Improperly Sized Air Conditioning Unit

An air conditioning unit that’s too large or too small for your space can lead to inefficiency and other problems, including freezing. A system that’s too large for the space may cool the air too quickly, causing the system to shut off prematurely and then restart, which can lead to freezing of the evaporator coils. A system that’s too small will struggle to maintain the desired temperature, working continuously to meet the demand and increasing the likelihood of freezing up.

Solution: Ensure that your air conditioner is the right size for your home or business. A qualified HVAC technician can perform a load calculation to determine the appropriate size unit for your space and recommend a replacement if necessary.

Steps to Take When Your AC Freezes Up

If you notice ice on your AC unit or it’s not cooling properly, here’s what you can do:

• Turn Off the AC: Continuing to run the AC while it’s frozen can cause further damage to the system. Turn off the unit and allow the ice to thaw. This may take several hours, so be patient.
• Check the Air Filter: If the filter is dirty, replace it with a new one to restore proper airflow.
• Inspect the Vents: Ensure all vents are open and unobstructed to allow air to circulate freely.
• Check the Thermostat: Make sure the thermostat is set correctly and functioning properly. If it’s not reading temperatures correctly, it may need to be recalibrated or replaced.
• Call a Professional: Once the unit has thawed, contact an experienced HVAC technician to inspect your system. The technician will check for common causes of freezing, such as low refrigerant levels, dirty coils, or airflow issues, and make the necessary repairs.

Preventing Future Freezing Issues

To avoid future freezing problems, regular maintenance is key. At Advanced Cooling, we recommend scheduling annual HVAC checkups to ensure your air conditioning system is in top condition. A professional maintenance visit typically includes checking refrigerant levels, inspecting the coils, cleaning filters, and ensuring that all components are working efficiently.

Conclusion

If your AC freezes up, it’s more than just an inconvenience—it’s a sign that something is wrong with your system. Addressing the underlying causes of the freeze is essential to restoring comfort in your home or business and preventing long-term damage. From dirty filters to refrigerant leaks, understanding the root causes and taking action quickly will save you time, money, and unnecessary stress.

If you’re in need of professional AC repair or maintenance in Texas or Oklahoma, Advanced Cooling has you covered. Since 2001, we’ve been providing courteous, affordable, and expert heating and cooling solutions to commercial and residential clients alike. Whether you need repairs, a system checkup, or a replacement, we’re ready to help. Give us a call today to schedule an appointment and get your air conditioning system back to full functionality!