Why Is My AC Freezing Up?

You count on your air conditioner to keep your home comfortable when the hot weather hits. When you notice that you’re still sweating during a heatwave even when the air conditioning is running, it could be a frozen evaporator coil. This is a very common problem. Your system might actually have ice form on the evaporator coil in some cases.

Symptoms of a frozen AC include:

  1. Air conditioner runs constantly
  2. Inside temperature does not decrease
  3. Blowing air feels warm
  4. Decreased air flow

Sources of Evaporator Coil Freezing

Two primary causes are responsible for a frozen air conditioner. First, the air filter may be old and clogged with dirt. This constricts all airflow. Reduced airflow means that less air is moving across the evaporator coil, which limits its ability to cool air. Restricted airflow could also result if you have placed something in front of an intake vent, which would essentially suffocate the system.

Second, the evaporator coil itself may be soiled with a thick layer of dirt and grime. The buildup of dirt prevents the air from touching the coil that contains refrigerant. Even if you have a clean filter and air is moving properly, your AC could freeze up when the coil is too dirty.

Aside from these two reasons, there are other situations that could be to blame for the malfunction. A refrigerant leak drops the pressure within the evaporator coil and makes it vulnerable to break down. It is also possible to freeze up an air conditioner if it is left running when the outside temperature is cool. Since AC is meant for hot weather, cool outdoor temperatures prevent the exterior unit, or condenser, from functioning properly.

Thorough AC Repairs

By the time that your air conditioner freezes up, the strain of reduced airflow or a refrigerant leak may have done other damage. Black Lion Heating & Air Conditioning can schedule air conditioning repairs as soon as possible in the area of Kirkland, WA. Our NATE-certified technicians will evaluate the causes of the freeze-up and provide accurate repairs. We do everything necessary to satisfy our customers completely because we want to maintain our reputation for trustworthiness and value. We’ll change the filter, clean the coils, replace broken parts, measure airflow, and confirm restoration of cool airflow before leaving your home.

How the Evaporator Coil Works

To understand the cause of a freeze up, it’s important to know how your air conditioner functions. The evaporator coil is located inside your house. It is usually integrated with your furnace so that both the heater and air conditioner can share a blower for moving inside air through the ducts.

Refrigerant fills the coils that are made from metals such as aluminum, copper, or steel. Thin metal fins also cover the coils for the purpose of drawing more air into contact with the coil. As the air intake sucks air into the coil chamber, the warm air hits the coil and fins. The refrigerant extracts heat energy from the warm air passing over the coil. This action cools the air that is then distributed to your rooms via the vents.

The refrigerant within the coil cycles between the coil and outdoor condenser during operation. As the condenser moves liquid refrigerant toward the coil, the liquid passes through a part called the expansion valve before it enters the coil. This part reduces the pressure on the liquid, which cools it down very quickly. This very cold liquid then enters the coil where it collects heat from the passing air.

The heat energy absorbed from the air heats the refrigerant and eventually transforms it from liquid to gas. As this happens, the moisture in the air condensates on the coil. Under normal circumstances, it drips and drains away. This part of the process reduces the humidity in your home. However, if the coil cannot perform correctly, the moisture can ice up the coil.

Can I Fix a Frozen Air Conditioner Myself?

The answer to this question is maybe. When the weather is blazing hot, you’ll naturally want to take action to restore function without waiting for a repair technician to arrive.

Start by changing the air filter. If the old one is obviously soiled and clogged, it may have been the complete source of the problem. You should also confirm that discharge vents are open and that the intake vent is not blocked. Once a fresh filter allows air to move freely, you can try starting the AC again to see if it begins cooling.

Homeowners may also choose to clean the evaporator coil. You can at least take a look at it to evaluate its condition before calling for service. For safety, you should cut the power to the AC system before removing the panel that covers the coil assembly.

You’ll be able to see right away how dirty it is. You can dislodge dirt with compressed air. When vacuuming up debris, try to avoid sending it into the ducts. Commercial evaporator coil cleaners are on the market and could be a good choice if you see a thick buildup of grime. These are meant to be sprayed on. The cleaner will eventually drip off into the drain system and, hopefully, take the dust and dirt with it.

If cleaning does not resolve the freeze up, then you may need to have the refrigerant checked by a professional. It is always okay to call a professional such as the ones on our team at Black Lion Heating & Air Conditioning in Kirkland.

What to Do After Unfreezing the AC

If you succeed in restoring the function of your air conditioner after it freezes up, then you should schedule an inspection at your convenience. The equipment would have been running under significant strain before you noticed its outright failure. As a result, you could have other parts on the verge of breaking.

The Importance of Seasonal Maintenance

You can avoid an alarming freeze up by getting an air conditioner tune-up at the start of the season. During maintenance service, a technician cleans the coil and condenser, checks the refrigerant, lubricates the fan belts, and evaluates the electrical connections. This service greatly reduces the possibility that you’ll have your AC freeze up.

Regular maintenance is important for prolonging the lifespan of your air conditioner. A cooling system represents a significant investment for most homeowners, and preventative maintenance allows you to get the most value from your dollar.

Comprehensive Home Services

The heating, cooling, electrical, and water heating systems at your home are complex machines. They are quite durable considering the daily use and wear and tear that they endure. Everyone needs to hire professionals to work on these systems from time to time, and Black Lion Heating & Air Conditioning in Seattle has earned a strong reputation for punctuality and technical expertise. We’re licensed and insured to repair air conditioners, furnaces, and water heaters. We specialize in Mitsubishi and Bryant installations, and we’re licensed electricians. For more information about our services, contact Black Lion Heating & Air Conditioning today.