What to Do if Your Evaporator Coil Freezes: 6 Steps to Try

If you’re wondering what to do if your evaporator coil freezes, chances are that it’s already happened. Your HVAC system has many essential components that allow it to operate efficiently to heat and cool your home. The evaporator coil is an essential part of the system. Simply put, its job is to hold the refrigerant and absorb the hot air from your home. But what happens if it freezes?

A frozen evaporator coil can cause the system to overheat, cause more problems to your HVAC system, and even permanently damage it if it’s not fixed properly. Let’s dive into what to do if the evaporator coil freezes, signs your coil is freezing up, and if you should hire an AC repair professional to fix it.

Why Does an Evaporator Coil Freeze?

Quite a few things can cause the evaporator coil to freeze. Here are a few other reasons why a coil will freeze:

• Dirty air filter: One of the most common causes of a frozen evaporator coil is a dirty air filter. This prevents the air from flowing properly over the coil and will cause it to freeze up.

• Blocked air ducts: If the air vents are blocked by furniture or other items, it’s likely preventing airflow and causing the coil to freeze.

• Blower is malfunctioning: The coil will get too cold and freeze up from lack of airflow if the blower is malfunctioning and not operating correctly.  

• Low refrigerant levels: The refrigerant cannot absorb enough of the heat from the air that passes over the coil. The moisture will then condense on the coil and form a layer of ice over it. 

• Dirty evaporator coil: The coil can become dirty with dirt and grime, which will prevent it from operating correctly. You should clean your evaporator coil once per year, and if they aren’t, they can freeze and cause further issues with the system.

How Much Does It Cost to Fix an Evaporator Coil?

The chosen fix method will determine how much it will cost to resolve your evaporator coil issue. For example, if you can replace the air filter yourself, it will cost $10 to $50, depending on the brand and type of filter.

However, the cost of replacing an evaporator coil ranges between $600 to $2,000, depending on the size of the coil. Keep in mind that cleaning and replacing your evaporator coil requires hiring an AC repair professional who can identify and fix your HVAC problem efficiently and safely.

4 Signs Your Evaporator Coil is Freezing

If you are experiencing HVAC problems, how do you know if it’s from your evaporator coil freezing up? There are a few things to watch out for to get ahead of this issue. Here are the most common signs the evaporator coil is freezing in your unit:

• Ice buildup on the outdoor unit: Head outside and inspect your outdoor unit. If you notice a layer of ice on the coil or system, that’s a strong indicator it is freezing.

• Warm air blowing from the vents: Does the air circulating in your home seem warm or hot when it’s supposed to be cold? That’s a common sign that the coil is frozen, which will prevent it from cooling the air properly.

• Reduced airflow: If the coil is frozen, it can restrict airflow, which can reduce the cooling capacity. Check your air vents to determine how strong the airflow is moving.

• Increased energy bill: A struggling HVAC system will use more energy to work, leading to unexplainably higher electric bills than normal.

What to Do if Your Evaporator Coil Freezes: 6 Key Steps

With HVAC systems, it’s best to hire an air conditioning company near you to inspect and fix any problems. It can be dangerous to attempt to fix it yourself, and you can sustain serious injuries or cause further damage to your unit.

However, here is what to do if the evaporator coil freezes and you want to troubleshoot it yourself before hiring a pro.

1. Turn Off the HVAC System 

The first thing you should do is turn off your HVAC system. Turn the thermostat switch to the “off” position. This step will prevent the system from turning on, giving it a chance to sit and thaw out. 

Some experts recommend shutting off the circuit breaker and allowing the system to thaw out over a 24-hour period. It’s also essential to ensure the system will not turn on while you are trying to inspect it for issues.

2.  Switch the Fan Setting 

Now that the system is off, you need to switch the fan setting from “auto” to the “on” position. Let it run for a few hours so it will blow warmer air over the coil. This step can help melt the ice and defrost the coil. Make sure to switch the setting back to “auto” once the coil unfreezes. 

3. Check the Air Filter

Remember that a clogged or dirty air filter can be the culprit of a frozen evaporator coil. So, take this time to check the filter and replace it if necessary. This method can prevent the coil from freezing in the future if that is the cause of the problem. 

4. Use a Hair Dryer to Warm the Coil

Be advised that this method can be dangerous and cause injuries if not done correctly. Depending on the circumstance, you may want to shut the system down at the breaker and hire an AC repair pro to take it from here. Plus, you will need to ensure you cut off all breakers associated with the unit, and wait the allotted time before switching it back on.

If you proceed, use the hair dryer on a low heat setting to slowly thaw out the coil and melt lingering ice. Be sure to avoid directly blowing the coil and stay at a safe distance away from the unit. You also need to ensure you don’t heat the coil too quickly. Otherwise, you will damage the coil. 5. Allow the Coils to Dry

5. Allow the Coils to Dry

Once the coil is thawed and ice is gone, allow enough time for the coils to dry out once they unfreeze. You can turn on the fan to dry out the area quickly. Wait several hours before ensuring the coil is dry enough to proceed. This waiting period will keep the coils from freezing up too fast once the unit is turned back on. Otherwise, the cold air can quickly cause an icy buildup to form back on the coil. 

6. Clean the Coil

Once the evaporator coil is completely dry, take this opportunity to clean it to avoid future issues and slowdowns with your HVAC system. This step requires hiring a local AC repair technician. The pro will scrub the coils carefully to remove dirt and debris. While the pro handles this step, visit your outdoor unit and be sure there aren’t any debris, leaves, or twigs stuck in the unit.

Tips to Prevent an Evaporator Coil From Freezing

Here are a few steps to prevent evaporator coils from freezing:

• Don’t block air vents: Make sure curtains, furniture, and other objects are away from all vents to ensure air is flowing properly.

• Change air filter regularly: How often you should change the filter depends on several factors. For instance, whether you have pets, the type of filter, or the air quality is poor, then you should replace it more often. A good rule of thumb is to replace it every one to three months. 

• Schedule regular maintenance: It’s good to have a professional perform maintenance twice per year to prevent coils from freezing and ensure your HVAC is operating efficiently. It’s best to have a professional inspect and maintain your unit in the spring and again in the fall. 

DIY vs. Hiring a Pro

Now you know what to do if the evaporator coil freezes. However, sometimes it’s best to call in a professional to figure out the problem so you don’t prolong the issue and risk further damage to your HVAC system. If the evaporator coil freezes up often, you should contact a professional AC repair technician near you to inspect the unit and fix what is causing it. 

Most HVAC technicians charge $75 to $150 an hour, but you will prevent further problems with your unit. If you avoid fixing the cause of the coil freezing, it will cost you much more later on if you don’t address the problem as soon as possible.