If you’ve noticed your air conditioner turning into a block of ice, you’re likely wondering: why is my AC freezing up? In Moncks Corner, SC, where summer heat and humidity are the norm, this issue can make your home uncomfortable fast. At Pointer Cooling and Heating, we’ve helped countless homeowners resolve freezing AC systems—and most of the time, the cause is preventable with proper care and maintenance.
Let’s walk through the common reasons your AC may be freezing up and what steps you can take to get things back to normal.
Poor Airflow Can Lead to AC Freezing Up
One of the most common reasons for an AC freezing up is poor airflow. When air doesn’t circulate properly across the evaporator coil, the refrigerant inside it gets too cold. Moisture from the air condenses and freezes, coating the coil in ice. That ice can continue to build until the system is fully blocked.
Poor airflow can happen for a few different reasons:
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Dirty air filters: If your filter is clogged, it restricts air movement.
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Blocked supply or return vents: Furniture or rugs may accidentally block vents.
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Leaky or crushed ductwork: This can restrict airflow or cause pressure imbalances.
Start by checking your air filter. If it’s dirty or hasn’t been changed in over a month, replace it. At Pointer Cooling and Heating, we recommend checking filters monthly—especially during high-use seasons like summer.
Low Refrigerant Levels Cause AC Freezing Up
Another major culprit behind your AC freezing up is low refrigerant. Refrigerant is the fluid that absorbs heat from your home. When levels drop—usually due to a leak—the pressure in the system decreases. That causes the refrigerant to get too cold, freezing the moisture on the coils instead of cooling your home.
Here are signs of low refrigerant to watch for:
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Ice buildup on the refrigerant lines or outdoor unit
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Hissing or bubbling sounds (especially near joints)
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Weak airflow or warm air blowing from vents
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Your AC runs longer than usual without cooling properly
Low refrigerant is not something you can fix on your own. It requires a licensed HVAC technician to locate the leak, repair it, and recharge the system. If you suspect a refrigerant issue, give Pointer Cooling and Heating a call. Our licensed technicians will safely get your system back to full performance.
Dirty Coils Are a Common Reason for AC Freezing Up
Over time, dirt, dust, and mold can collect on your evaporator coils, especially if filters aren’t changed regularly. When those coils get too dirty, they can’t properly absorb heat. That heat imbalance causes the coils to get colder than intended, eventually freezing up.
Dirty coils also reduce your system’s overall efficiency. You may notice higher energy bills, uneven cooling, or humidity problems in your home. And once the ice starts forming, it can spread to other components like the refrigerant lines or blower motor.
While some homeowners attempt to clean coils themselves, this job is best left to professionals. Our team at Pointer Cooling and Heating uses specialized tools and cleaning solutions to safely remove buildup without damaging the system.
Thermostat Problems May Cause Your AC to Freeze
Sometimes the issue isn’t with the AC unit itself—it’s with your thermostat. If the thermostat is faulty or placed in a location that gives inaccurate readings, it can force the system to run too long. When an AC runs continuously without proper cycling, the temperature of the refrigerant can drop too low, triggering freezing.
Other thermostat issues include:
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Short cycling (turning on and off rapidly)
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Never reaching the desired set temperature
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Display errors or failure to respond
Try replacing the batteries first if your thermostat is acting up. If that doesn’t help, one of our experienced technicians can test and recalibrate the unit—or recommend a smart thermostat upgrade that better fits your home’s needs.
Outdoor Temperatures Can Trigger AC Freezing Up
Although it’s rare in Moncks Corner’s summer heat, outdoor temperature can sometimes be the cause. If the weather cools unexpectedly (especially at night during spring or fall) and your AC continues to run, it may freeze. Most systems aren’t designed to operate efficiently when the temperature drops below 60°F.
To prevent this, avoid running your air conditioner overnight if outdoor temperatures dip below 60°F. If you still need airflow, use the fan setting instead of cooling mode. A programmable or smart thermostat can help manage this automatically.
Oversized Systems and AC Freezing Up
In some cases, the issue lies in your AC system’s size. An oversized unit may cool your home too quickly without running long enough to dehumidify the air. This leads to excess moisture, which can settle on the coils and freeze. It also causes uneven temperatures throughout the house and shortens your system’s lifespan.
Unfortunately, there’s no easy DIY fix if your system is too large. But we can help. At Pointer Cooling and Heating, we offer full system inspections and load calculations to determine if your unit is properly sized for your space.
What to Do If Your AC Is Freezing Up
If you find your AC is frozen, here’s what you should do right away:
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Turn off the system completely, and switch the fan to the “on” position. This helps circulate warm air and melt the ice.
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Do not try to break off the ice manually—you could damage the coil.
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Once the system is thawed, check your air filter and thermostat. Make sure all vents are open and unobstructed.
If the problem persists or ice forms again, it’s time to call in the pros. Freezing can lead to bigger issues if left unresolved—like compressor failure or water damage.
Call Pointer Cooling and Heating for AC Repair in Moncks Corner
Still asking yourself why your AC keeps freezing up? Don’t let the problem continue or worsen over time. The experts at Pointer Cooling and Heating are here to help with honest service, quick response times, and quality repairs done right the first time.
Whether it’s a refrigerant leak, thermostat malfunction, or something more complex, we’ll get to the root of the issue and restore comfort to your home. Call Pointer Cooling and Heating today for reliable AC repair in Moncks Corner, SC
