Understanding Why Your AC Freezes Up
If you’ve ever walked past your air conditioning unit and noticed ice forming on the coils or refrigerant lines, you’re probably wondering, “What causes AC to freeze up?” This frustrating problem not only reduces your system’s cooling performance but can also lead to costly damage if ignored.
At Riverside Comfort Care, we’ve helped countless homeowners in Fort Smith, Van Buren, Alma, and Greenwood, Arkansas solve this exact issue. Let’s break down the most common causes, what you can do to prevent them, and when it’s time to call a professional.
1. Low Refrigerant Levels
Low refrigerant is one of the top answers to what causes AC to freeze up. Refrigerant absorbs heat from your home, and when it’s low, the pressure inside your evaporator coil drops — causing the temperature to fall below freezing and ice to form.
Common signs of low refrigerant:
Weak airflow from vents
AC running longer than usual
Hissing or bubbling noises from refrigerant lines
If you suspect low refrigerant, do not try to top it off yourself. The U.S. Environmental Protection Agency (EPA) requires refrigerant handling by certified technicians due to environmental and safety risks (EPA Refrigerant Rules).
For safe refrigerant checks and recharging, schedule an AC repair with Riverside Comfort Care.
2. Restricted Airflow
Airflow issues are another leading cause of a frozen AC. Without enough warm air passing over the evaporator coil, the coil gets too cold and ice begins to build up.
Possible airflow restrictions include:
Clogged or dirty air filters
Blocked supply or return vents
Damaged ductwork
Prevention tip: Replace your air filters every 1–3 months, especially during peak cooling season. ENERGY STAR notes that clean filters not only improve air quality but also enhance AC efficiency.
Need help? Our HVAC maintenance service includes filter changes, airflow checks, and duct inspections.
3. Thermostat Problems
A malfunctioning thermostat can cause your AC to run longer than necessary, dropping coil temperatures too low. In some cases, incorrect thermostat placement (like near a drafty window) can cause false readings, leading to overcooling.
Solution: Calibrate or replace the thermostat and consider upgrading to a smart thermostat for more accurate temperature control.
4. Dirty Evaporator Coils
Over time, dust, pollen, and grime can collect on your AC’s evaporator coils. A dirty coil can’t absorb heat efficiently, leading to lower coil temperatures and freezing.
Signs your evaporator coil may need cleaning:
Weak cooling
Ice forming on the coil
Higher than normal energy bills
Professional coil cleaning is part of our AC maintenance services and helps prevent this issue.
5. Blower Motor Issues
Your AC’s blower motor is responsible for pushing air across the evaporator coil. If it’s not working properly due to electrical problems, worn bearings, or motor failure, airflow will be reduced — and ice can form.
Warning: Blower motor repairs involve electrical components and should only be handled by a licensed HVAC technician.
6. Running the AC in Cool Weather
Running your AC when outside temperatures are too low (typically below 60°F) can cause refrigerant pressures to drop, resulting in a frozen coil.
If you need cooling on a mild day, consider using your system’s fan-only mode instead.
7. Drainage Problems
When condensation from your evaporator coil can’t drain properly due to a clogged condensate line, water can back up, freeze, and spread ice throughout the system.
Prevention: Schedule seasonal maintenance to have your drain line flushed and inspected.
Why Ignoring a Frozen AC Is a Big Mistake
If you ignore the problem, you risk:
Damaging your compressor (one of the most expensive parts to replace)
Shortening your AC’s lifespan
Increasing your energy bills
Turning off your AC and letting it thaw is a temporary fix — but you still need to address the root cause to prevent future freeze-ups.
How to Prevent AC Freeze-Ups
Here are simple steps homeowners in Fort Smith, Van Buren, Alma, and Greenwood can take:
Change air filters regularly
Keep vents unblocked
Schedule seasonal AC tune-ups
Monitor refrigerant levels with professional service
Keep the outdoor unit clear of debris
When to Call Riverside Comfort Care
If your AC is frozen or you notice weak cooling, unusual noises, or water leaks, contact Riverside Comfort Care right away. Our licensed technicians will:
Diagnose the cause of the freeze-up
Repair or replace faulty components
Recharge refrigerant safely
Get your home cool and comfortable again
We proudly serve Fort Smith, Van Buren, Alma, and Greenwood, offering same-day service for urgent cooling issues.
Stay Cool — Schedule Your AC Repair Today
Don’t let a frozen AC ruin your comfort. Call Riverside Comfort Care at (479) 431-4884 or request service online. Our experienced team is ready to keep your home cool and your AC running efficiently all summer long.
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