A frozen air conditioner is a warning sign that something's not working properly inside your system. Whether it's poor airflow, low refrigerant, or a mechanical malfunction, ignoring the problem can lead to costly damage and longer periods without cooling.
What Causes an AC to Freeze Up?
To understand what causes an AC to freeze up, you need to know how your system works. Your air conditioner relies on the movement of warm air across cold evaporator coils. When something disrupts this process, either by reducing airflow or throwing off the refrigerant balance, the temperature of the coils can drop below freezing. Moisture in the air then freezes on the coils, forming layers of ice that block proper operation.
Low airflow is one of the most common causes. If air isn't moving over the coils fast enough, they stay too cold, and ice starts to build. This can be caused by dirty filters, blocked vents, or even malfunctioning blower motors.
Low refrigerant levels are another major factor. When refrigerant pressure is too low, it can cause the evaporator coil to become abnormally cold. This results in a frozen AC unit that can't cool your home effectively and may suffer long-term damage if left unchecked.
Why Does My AC Keep Freezing?
If your AC keeps freezing even after it's been thawed and restarted, there's likely a persistent underlying issue that hasn't been addressed. Continuous freezing is a sign that your system is under stress and in need of professional evaluation.
Recurring freezes usually indicate one of the following:
Ongoing airflow problems, like a clogged filter or undersized ductwork
Refrigerant leaks, which are not only harmful to your system but also to the environment
Thermostat or control issues, which can cause your system to run longer than necessary and lead to overcooling
Drainage problems, where moisture from condensation isn't being properly removed, allowing ice to accumulate
Repeated freezing puts unnecessary wear and tear on your compressor and coils. If your AC unit keeps freezing up, it's best to turn it off and schedule a professional inspection from MR. HVAC in Kennesaw as soon as possible.
What to Do When Your AC Unit Freezes Up
It's important to act quickly when you notice your AC unit freezing up. The longer you wait, the more likely the system will suffer long-term damage. So if you spot ice on the outdoor unit, see water pooling around the system, or feel warm air coming from your vents, here's what to do:
Step 1: Turn Off the System
The first thing you should do is shut off the system at the thermostat. Running a frozen air conditioner can burn out the compressor and make repairs far more expensive.
Step 2: Let It Thaw
Give the system several hours to fully thaw. This may take time, especially if there's a thick buildup of ice. Don't try to chip away the ice manually because this can damage the coils.
Step 3: Check the Air Filter
A dirty or clogged air filter is one of the simplest reasons why air conditioners freeze up. Replacing or cleaning it can restore airflow and prevent future freezing.
Step 4: Inspect Vents and Registers
Make sure nothing is blocking your return or supply vents. Restricted airflow from furniture, rugs, or closed vents can interfere with circulation and cause icing.
Step 5: Call a Professional
If your system continues freezing or won't turn back on after thawing, it's time to contact a licensed technician at MR. HVAC in Woodstock. The issue could be more serious, like a refrigerant leak or faulty blower motor.
Why Do Air Conditioners Freeze Up in the First Place?
The root of the problem often lies in one of two areas: airflow and refrigerant pressure. These are the two main components of a balanced AC system. When either one is off, the system can't remove heat effectively, causing the evaporator coil to become too cold.
Let's break it down further:
Airflow Restrictions
Blocked or limited airflow prevents warm indoor air from reaching the cold evaporator coil. Without enough heat exchange, the coil temperature drops and condensation freezes on contact. Dirty air filters, closed dampers, collapsed ducts, or a failing blower motor are all potential airflow disruptors.
Refrigerant Issues
Refrigerant absorbs and transports heat. If there's too little in the system due to a leak or improper charge, the pressure inside the coil drops, causing it to become too cold. That's one of the top causes of air conditioners freezing up, and it always requires professional diagnosis.
Common Signs Your AC Unit Is Freezing
Sometimes the signs are obvious, like visible frost or ice. Other times, the symptoms are more subtle. If you suspect your system may be freezing, watch for these red flags:
Ice forming on refrigerant lines or outdoor unit
Little or no cool air from the vents
A system that runs continuously without cycling off
Unexplained water puddles near the indoor unit
High energy bills despite poor cooling
These are all indicators that something's wrong internally. Knowing what to do when your AC unit freezes up can help you catch the issue early and avoid more expensive repairs down the road.
How MR. HVAC Can Help When Your AC Is Freezing Up
At MR. HVAC, we specialize in diagnosing exactly what causes an AC unit to freeze up and fixing it fast. We get to the root of the issue, whether that's refrigerant loss, airflow blockages, or a component failure.
Our trained HVAC technicians handle everything from filter replacements to full system diagnostics and refrigerant recharges. If your system is freezing due to age or inefficiency, we'll also help you evaluate replacement options that better suit your home's cooling demands.
We're proud to serve our local Atlanta community with honest, high-quality HVAC repair and maintenance.
Summary: Don't Ignore a Frozen Air Conditioner
Knowing what causes air conditioners to freeze up helps you respond quickly and prevent problems. Whether it's your first freeze-up or an ongoing issue, MR. HVAC in Roswell is here to help with expert service and straightforward answers.
Need Help with a Freezing AC Unit?
If your AC unit keeps freezing up, don't wait for it to cause permanent damage. MR. HVAC can get your system back on track quickly. Our team will pinpoint the cause, make the necessary repairs, and help prevent it from happening again.
Call MR. HVAC today at 770-213-4111 or schedule your service online. We're here when you need us most.