Indoor AC Coil Freezing Up? Here’s What It Means
Key Takeaways
Frozen indoor AC (evaporator) coils are a common issue that can reduce cooling performance or stop airflow altogether. In most cases, freezing is caused by restricted airflow, dirty air filters, faulty fans, thermostat issues, or refrigerant leaks. Turning off the system and allowing the ice to melt is an important first step, but professional service is often needed to identify and fix the root cause. Regular HVAC maintenance is the best way to prevent evaporator coils from freezing and to keep your system running efficiently.
Frozen AC coils can occur for a variety of reasons, causing your air conditioner to work less efficiently or completely stop airflow. If you see that your indoor AC coil is frozen, you obviously have a problem. This indicates an issue that needs attention. If your indoor AC is not accessible and you can’t see the coils, you may be wondering whether frozen coils are the problem. Find out more about how a climate control unit’s coils can ice up and how to fix them.
What Happens When Evaporator Coils Freeze Up?
When an indoor cooling system’s coils are icing up, you may notice these symptoms:
- Your AC is running, but it is not cooling your house
- Instead of cool air, you feel warm air coming out
- You can see ice on the evaporator coils
- Moisture builds up around the AC in the form of condensation or puddles of water
Does this describe your situation? Keep reading to learn more about the causes of frozen coils and what you can do about them.
Why Are My Evaporator Coils Covered in Ice?
There are several reasons a climate control system can experience frozen AC coils. The evaporator coils could be icy because:
Air Filter Is Dirty
Dirty air filters are the number one cause of icy evaporator coils. A dirty air filter prevents air from reaching the evaporator coils, which can cause them to get too cold and freeze. Replacing the air filter could solve the problem.
Broken AC Fan
Even with a clean air filter, the air can’t reach the coils without a fan. If your fan has stopped working or the blades are stuck due to grime, your coils could get too cold and freeze.
Blockage in Return Vents
Proper airflow is key to keeping your evaporator coils working properly. Blocked air return vents disrupt the airflow cycle, which can cause frozen AC coils. Take a look around your home, locate the air return vents, and make sure nothing is covering them.
Thermostat Not Working
A broken or faulty thermostat could be the problem, especially if you notice that the AC only freezes at certain times of the day. For instance, if the outdoor temperature drops overnight and the thermostat does not tell your AC to stop, the coils could get too cold and freeze by morning.
Refrigerant Leakage
The refrigerant that runs through your evaporator coils helps it absorb heat. If there is a leak in the refrigerant line, your coils may not be absorbing the heat they need to work properly, leading to frozen condensation. If you hear a hissing sound around the indoor HVAC coils or notice an oily residue, you may have a refrigerant leak that requires professional attention.
How Can I Fix Frozen AC Coils?
If you have frozen evaporator coils, the first thing you should do is turn off the AC unit. Allowing it to run with frozen coils could lead to more problems, including complete system failure.
The best next step is to call one of our trained HVAC technicians. We can identify the problem and let you know what it will take to get your AC working again.
While you wait for a professional to arrive, you could try melting the ice. Shutting down the AC system will start the melting process. If you can reach it with a hair dryer, you could blow warm air at it to melt the ice faster. Do not try to chip the ice off the coils, as that could damage them. Melting ice will create a puddle of water, so be prepared to clean up excess moisture.
How Can I Prevent Indoor Evaporator Coils from Icing Up?
The best way to prevent your AC coils from freezing is to schedule regular maintenance for your HVAC system. During regular maintenance, our technicians inspect the system, clean it, replace air filters, and check for refrigerant leaks. This can go a long way toward stopping problems before they start.
Get Your AC Up and Running!
The professionals at Mid-Fla Heating and Air are ready to help with your indoor AC problems. If your AC coils are freezing up, contact us as soon as possible.
