Why Do Air Conditioners Freeze Up

Why is My Air Conditioner Line Covered in Ice?

It’s a surprising sight in the desert heat, but icing of air conditioner components is a common problem. Even a Phoenix homeowner may find an air conditioner drain line covered in ice. This is a severe problem that could leave you with a sweltering home and sky-high electric bills if not addressed promptly. Fortunately, it is often preventable. Regular maintenance and a few DIY steps may rid your AC line of ice and keep the unit running smoothly. When those measures aren’t enough, air conditioner experts can help.

Causes of Frozen Refrigerant Line

Numerous issues lead to an iced-up air conditioner line. Some reasons are obvious, but it may take a bit of detective work to figure out what is wrong. Problems that can lead to ice build-up include:

Low Refrigerant Charge

Refrigerant flows through a closed system, so if the refrigerant charge is low, this indicates a leak somewhere in that system. Leaking valves may be the culprit.

Clogged or Dirty Evaporator Coils

Faulty evaporator coils keep refrigerant from moving correctly through the system which can also cause the air conditioner line to freeze. They need to be cleaned and may require professional service.

Air Filter Problems

Sometimes the problem is as simple as a dirty air filter that needs to be cleaned or replaced. This can often be handled as a DIY project.

Capacitor Malfunction

A failing capacitor affects the functioning of the blower motor, which may cause it to run slowly or stop running altogether.

A Stuck Contactor

This could cause the outside unit to run when it is not supposed to, or prevent it from entering cooling mode.

Excessive Air Conditioner Use

While it is certainly tempting to keep the air conditioner on at full-blast all summer, this can lead to operating issues. Only run the unit as long as you need to keep your home comfortable, and try to keep the thermostat set above 72 degrees Fahrenheit, especially in colder weather.

Several of these problems involve restricted airflow over the evaporator coils. Your AC unit relies on the flow of uncooled air over these coils to keep them from freezing. When that airflow stops or drops too low, ice builds on the coils and moves down the refrigerant line.

DIY AC Fixes

The first step you should take when you find your air conditioner line frozen is to turn the air conditioning unit off and turn the fan on. Taking this step allows the frozen line to thaw over a few hours, and prevents costly compressor damage. Once the ice has melted, check for problems that are easy to fix, such as dirty air filters or blocked vents. You should check the condition of the air filter once a month. If it appears to be dirty, you will need to clean it or replace it to keep air flowing properly over the evaporator coils. Also, you should check the return vents that pull air from the building into the air conditioning system. These may be blocked inadvertently by furniture or by window coverings, hindering airflow.

Finally, check that all the supply vents in your home are open and unobstructed. Supply vents allow cold air to flow through the house, but homeowners often cover them or close them in rooms they do not frequently use. While this may seem like an effective way to save on cooling costs, it increases pressure on the air ducts and makes the air flow less efficient. The AC unit works overtime to keep the air moving, which may eventually damage the system.

Keep checking the AC unit for ice after it thaws because, unfortunately, it could ice up again. Even somebody highly skilled in home repairs may not be able to fix problems leading to frozen air conditioner lines themselves. If you cannot find the source of the icing issue or basic maintenance and checks of the air vents and the air filters do not solve the problem, then it is time to call a professional.

Get Professional AC Repair Help

Although it is understandable that people want to fix as much as possible on their own, some AC problems are best handled by a professional technician. These are repairs that could be dangerous to an inexperienced or untrained person, or that could lead to more expensive problems. Some of these include:

Cleaning clogged evaporator coils
Fixing a leak in the refrigerant line
Replacing a malfunctioning capacitor
Replacing the compressor

If you have questions or need help, call our experts at Day & Night Air. Our technicians will professionally repair your air conditioning system in Phoenix to make sure that it runs efficiently during summer heat waves, and throughout the year. We provide AC repair in Phoenix 24 hours a day, seven days a week all year to give you peace of mind every day.