May 10, 2021

Even if you have not experienced it for yourself, you have likely seen the evidence of a frozen air conditioner. The frosted refrigerant lines and the iced-over compressor are almost beautiful when you see them. But what causes it, does it harm your system, and what can you do when it happens?

Are Air Conditioner Freezes a Problem?

When your system is working properly, you will barely notice that it is running, aside from the sound of the circulating fan. If you are outside, you may notice the sound of the condensing unit as well.

However, if you notice a freeze somewhere in the system, it is a sure sign your unit is malfunctioning. If left unrepaired, frozen parts of your system can damage your lines, your evaporator and condensing coils, and your compressor.

Frozen sections in your air conditioning system also prevent the unit from cooling your house effectively. This means not only will you experience more repairs as a result, but your cooling expenses will climb, too.

Understanding Why Your System Freezes

To understand why your AC unit freezes, you must also understand a little about how your system cools your home. The entire unit works by circulating refrigerant and air. The refrigerant cools the air the system circulates through the appliance.

The way the refrigerant works is by absorbing the heat the air in your unit contains and venting it outside. It does this by your air conditioner regulating the refrigerant pressure at various points in the system.

When the pressure decreases, the refrigerant becomes extremely cold, allowing it to absorb heat from the air. When the pressure is high, it becomes extremely hot, allowing it to transfer the heat to the air outside.

If there is a problem with either circulating the air or the refrigerant, your air conditioner may become frozen. Here are some of the top problems in your system that may result in a frozen section.

Low Refrigerant Level

The most obvious cause people associate with their system freezing up is low refrigerant. When the AC unit does not have enough refrigerant, it cannot build the pressure at the condensing coil. The compressor then works overtime to try to create the pressure, causing lower pressure in the refrigerant line. This results in the line becoming cold.

This low refrigerant is caused by a leak somewhere in the system. This leak can occur in the refrigerant lines, at the evaporator or condensing coils, or even at the compressor.

Airflow Restrictions

If the air cannot flow properly through the cooling system, then the refrigerant cannot absorb heat from it. Lacking heat, the refrigerant stays too cold, causing it to freeze in the evaporator coil and in the refrigerant lines.

These airflow restrictions are commonly linked to only a few issues. The most common is dirty air filters. The next is a dirty evaporator coil, which is caused simply by airborne contaminants settling on the coil tubes. The circulating fan wheel also collects some of these contaminants, which reduces the vacuum it creates when drawing air into the unit.

Mechanical Problems

Various mechanical issues may also cause the air not to flow or the refrigerant not to pressurize properly. The compressor is one of the most common mechanical components to cause a frozen block, especially if it has a leak.

The circulating fan motor may also lead to a freezing problem if it is burning out. When this component fails, it may cause the wheel to open more slowly, leading to reduced air circulation.

What to Do if Your System Freezes

If you see a frozen component or suspect a part of your system has frozen, shut down the AC unit. Give it time to thaw before starting it up again. While you are waiting, be sure to check your air filters to ensure they are clean.

Once the system is thawed, turn it back on and observe what is happening. Did the compressor and condensing unit start? Were there any screaming, buzzing, rattling, or screeching sounds coming from the outside unit? If any of these occur, call a professional technician to solve the problem.

Also, consider doing the work needed to prevent the freeze-up in the first place. When you have your system properly maintained in the spring, you can avoid many of these issues. Your technician will clean the circulating fan and evaporator coil. They will also test each of the components to ensure they are working properly, along with inspecting the amount of refrigerant in your system.

People throughout American Fork have turned to Gunthers Heating, Cooling, and Plumbing for air conditioning problems like freezes since 1910. Our team proudly provides heating and air conditioning installation, maintenance, and repair, along with a full range of plumbing services. Call to schedule your air conditioning repair or maintenance with one of our expert technicians today.

company icon