How to Avoid Frozen Air Conditioner Coils

A common cause of air conditioning system failure is related to frozen coils. This can cause your AC system to fail when you least expect it.

A frozen aircon coil causes the whole system to struggle to perform and if left untreated can end in complete system failure. One way to avoid this is to ensure proper maintenance performed regularly. 

In fact, the maintenance that would have prevented the failure will cost much less than the repair bill will be to fix it.

This preventative maintenance can be done by yourself but you should also ensure your system is regularly serviced by licensed air-con contractors.

What Causes Frozen Coils?

It is important to understand what causes frozen coils so you can avoid them. When you work with a professional, you will prevent frozen coils as they are experienced in fault finding and proper servicing.

Here are the most common cause of frozen coils:

  • Broken Blower Fans

Fans suck and blow air through the indoor and outdoor AC units. Due to the friction of movement they need sufficient lubrication. Dirt and dust could also lead to faulty fan motors.

Fans must perform properly by pushing air through the air conditioner. When air cannot flow as it should, this could lead to frozen coils.

  • Malfunctioning Thermostats 

Frozen coils could also be a result of a malfunctioning thermostat. This is an important part of every air conditioner that helps in regulating temperatures. 

It helps in preventing the AC from overworking just to have a consistent temperature. This is important if you are to enjoy the cool air in your home.

If the thermostat has malfunctioned, it could lead to the system overworking and eventually wearing out. 

Despite its work being regulating temperature, it could improperly control the AC. If such issues are not fixed when noticed, this could lead to frozen coils.

  • Dirty Air Filters

One of the ways that air conditioners are maintained is by cleaning. Different components are cleared off dirt and debris. This is to ensure quality airflow.

What dirty filters do is to obstruct quality air. Clear airflow prevents the coils from getting too cold.

If the filters are not cleaned regularly, the coils get cold, which leads to freezing. 

  • Refrigerant Leaks

Refrigerant leaks are a major problem for air conditioners. They lead to big issues that could lead to a replacement. 

Refrigerant is essential in heat absorption as it helps in changing temperature and pressure. More heat is absorbed whenever there is leakage.

The problem when more heat is absorbed than necessary is that it causes coils to freeze. Rather than adding this chemical, a technician should first repair it.

This will prevent frozen coils in the future. 

  • Blocked Condensate Lines

Clogged pipes from condensed moisture also lead to frozen coils. The problem starts when condensate lines are blocked. 

Instead of the lines removing excess moisture from humidity, they are blocked and thus cannot perform their duty. If there are clogged pipes and the condensed moisture is not eliminated properly, the system will struggle with frozen coils. 

How to Identify Frozen Coils

In some instances, you can easily tell that your air conditioning system has frozen coils. Although some issues will need a professional, you can tell when the AC is about to fail.

If you have noticed water leaks in the building or some kind of condensation, coils could be frozen. Moisture starts to build up and this is the reason you will see wet areas in the building. 

Perhaps, the air is not flowing or it is warm. This is when you check the supply registers. If you notice warmth or failure, your coils could be frozen.

What to Do When You Suspect the Coils Are Frozen

In case the system has frozen air coils, you should not worry but have it fixed as soon as possible. It is even better when you can tell what caused the coils to freeze. 

If it continues to run with this problem, there is a chance that the compressor will fail. To avoid this and any further damage, you should talk to a technician. 

The first thing you need to do is switch the unit off before the professional comes. Avoid trying to fix the problem and hire a trustworthy technician. 

How to Prevent Frozen Coils

Different issues will lead to frozen coils and when each is prevented, this problem can be avoided. Preventative maintenance is the best way to eliminate these issues.

Preventative maintenance means that an HVAC expert inspects, cleans, and repairs the air conditioner regularly. Whether the coils need to be cleaned, filters changed or refrigerant lines inspected for leaks, the specialist will undertake all this.

If you are to enjoy the utmost performance of your AC, small problems should not be left unchecked. With regular maintenance, small problems are noticed and repaired early. 

This is also a habit that will save you money in the long run as it will be preventing major issues. Remember that the more issues the system experiences, the more money you spend.

When Is the Best Time to Have Maintenance Done

During summer, air conditioners tend to run for longer. The heat would be unbearable if they are not used.

Without proper maintenance, the system could fail. This is one thing you cannot imagine happening. 

For this reason, the AC should be checked before summer. If it has not been in use for long, its components need to be checked.

Refrigerant levels should be checked, corroded wires replaced, and air filters cleaned. Once this is done, you do not have to worry about frozen coils in summer.


Frozen air conditioner coils happen due to numerous things. It is the small unchecked problems that turn into such issues.

For example, if the condensate line is blocked, the fan’s motor is faulty or the air filters are dirty, the unit will likely experience the problem.

Signup for a preventative maintenance program with your local HVAC specialist. They will help in detecting early issues and preventing costly repairs. 

If you notice that your system has issues, call an air conditioner expert as soon as possible. You may be tempted to melt ice on the AC but it is best to work with a professional.