What To Do When Your AC Unit Freezes Up

air conditioner filter causing frozen ac unit

Air conditioners are designed to provide a cooling effect but they are not supposed to freeze. If they do, then it means something has gone wrong to upset the balance. The AC system won’t be able to perform the way it should and your home will not get as cool as you want it to be. In this article, we discuss why this happens, what to do when your AC unit freezes up, and how you can prevent a recurrence.

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Why Air Conditioners Freeze Up

1. Dirty HVAC Air Filters

The air conditioner requires good airflow for optimum performance. If it can’t get enough air to flow through the evaporator coils, then it will freeze up. A steady stream of air regulates coil temperatures by transferring its heat over to the refrigerant. This is important since the chemical tends to range from 10-20 degrees Fahrenheit at this point. The culprit for poor airflow could be dirty air filters. The dust build-up can prevent air from getting into the system.

2. HVAC Airflow Obstructions

image of a homeowner placing hands in front of hvac air vent to check for airflow

If you are diligent in replacing the air filters yet you still encountered a frozen air conditioner, then there might be airflow issues in other places around the system. Perhaps there are blocked vents and registers around the house. Look around to see if furniture or other objects are too close to their locations. Adjust accordingly. If freezing is frequent, then the air conditioner problem might be poor ductwork design or installation. It could also be a sign of pest infestation. HVAC professionals can evaluate the situation and fix the problem.

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3. Air Conditioner Refrigerant Leaks

A frozen air conditioner might also indicate a low coolant level due to a refrigerant leak. Additional signs include a hissing sound and the surge of hot air from the air conditioner. Sealing the leak quickly is vital. New coolant is also necessary to get back to the optimum level. Homeowners should not attempt to do all of these themselves because the chemicals can be toxic. Allow the expert HVAC contractor to handle the situation as they have the proper tools and training to perform these tasks safely.

4. Dirty Evaporator Coils

dirt on air conditioner coils

Lastly, consider the possibility that the evaporator coils themselves are problematic. Perhaps they have gotten dirty over time because of the build-up of dust and grime. These can reduce heat transfer between the air and the coils. The dirt can also cause clogs in the condensate lines. The trapped water can freeze up. The same is true for the coils. The system will have to overwork under these conditions.

What To Do If Your Air Conditioner Freezes

1. Thaw The Air Conditioner

If you discover that your AC has frozen, then you should turn the unit off to prevent things from getting worse. Without power, the ice should thaw by itself so homeowners can simply wait for this process to finish. Just remember that this can take several hours. It’s best to do this right before you leave the house for work. Do open the windows and use fans for alternative cooling if you have pets inside. Never use a sharp tool to break the ice as this can make matters worse.

2. Dry The Coils

After the ice has melted, the coils are going to be wet for some time. Bring the power back on and run the blowers to help things dry faster. Don’t turn the air conditioner yet. Only the fans should be running for better air circulation and faster moisture evaporation. Check back after a few hours. You can use the air conditioner normally after it has dried up inside.


How To Prevent Freezing In Your Air Conditioner

Avoid this headache in the future by taking good care of your cooling system. Perform the following on a regular basis:

1. Change The Air Conditioner Filters

image of an air conditioner filter replacement

HVAC air filters prevent unwanted airborne particles from getting into the system. They are vital in keeping the equipment clean and improving air quality for the house occupants. However, these cannot stay indefinitely. The build-up of dust on its surface will gradually choke the system. At a certain point, they need to be replaced by fresh ones to maintain the balance between purification and airflow. Check your filter on a monthly basis. Replace the filter when it is necessary.

2. Check Coolant Levels

The amount of coolant in the system should not dip below a certain threshold. Otherwise, various problems will start to arise. Make it a habit to call HVAC technicians for air conditioner maintenance. During their annual visit, they can check the coolant levels to ensure that the AC system is working within parameters. If it is too low, then they can recharge the system. If there is a leak, then they will fix it for you.

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3. Clear Obstructions

Air conditioner maintenance technicians will also check whether there are obstructions affecting the airflow. They will identify these and inform you about the situation. Changes can then be made to rectify the situation and improve AC performance. This could be as simple as moving furniture around. However, there are cases wherein the ductwork will have to be modified. Leave it to the experts to get the work done.

4. Clean The Air Conditioner Coils

If dirty coils are causing the problem, then they will need a thorough cleaning. Pay special attention to the condensate lines as this might have a clog. HVAC technicians can open the system and remove the clog to allow water to flow without impediments. This is part of the preventive maintenance checklist as well.

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Your AC unit is your best friend during hot summers. Take care of it so that it can take care of you. Schedule preventive maintenance from a trusted HVAC contractor to avoid frozen coils and other common air conditioner issues.

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