If your air conditioner isn’t cooling like it should or, worse, is blowing warm air, it could be due to your AC evaporator coil freezing up. This common issue can have a significant impact on your home’s comfort and energy bills.
Apollo Air Heating & Cooling is the leading provider of expert air conditioning services in Boerne, Texas, and we often get calls from customers wondering why ice is building up on their indoor coil. Let’s walk through the top six causes of frozen evaporator coils and what to do to restore efficient cooling power when you need it.
1. Low Refrigerant Levels Can Trigger Icing Trouble
Refrigerant is essential to your cooling system, as it’s the only way it absorbs heat from indoor air. Even a tiny pinhole leak can be a significant problem. Pressurized refrigerant gets forced out rapidly. As the pressure drops, the coil’s temperature will fall below freezing, causing water vapor to turn into ice. Watch out for hissing sounds, weak airflow, and visible frost as warning signs of this problem.
Handling refrigerants is not a DIY project. It requires EPA-certified expertise. If you suspect a leak, reach out to your trusted local HVAC expert for safe, prompt repairs.
2. Restricted Airflow Is the Most Common Cause of AC Evaporator Coil Freezing
Every air conditioning system depends on unrestricted airflow to operate correctly. When air cannot freely pass over the evaporator coil, it will fail to absorb heat and moisture properly. That quickly causes the coil exterior to supercool and freeze ambient water vapor. In and around Boerne, where pollen and dust are ever-present, restricted airflow is especially common.
Several factors contribute to this issue:
- Dirty air filters block airflow and reduce efficiency
- Blocked vents choke off circulation
- Dusty ductwork or coils restrict air movement.
Keep the areas near vents open and clean. Check your HVAC system air filter every 30 days and change it when it’s dirty. In any event, change it no less than every 90 days.
3. A Faulty Blower Fan Means Air Isn’t Moving Like It Should
The blower fan drives air across the evaporator coil. When the fan slows or fails, airflow suffers, causing weak airflow that can freeze coils. Also, listen for odd noises and check for uneven temperatures from room to room.
Our technicians often find aging motors, worn capacitors, or loose belts behind these issues in and around Boerne. If your home feels stuffy or your vents are unusually quiet, it’s likely time for a professional inspection.
4. Thermostat Issues Can Cause Overcooling or Miscommunication
Your thermostat doesn’t just manage temperature. It’s the control center of your cooling system that tells it when to start and stop. If it sends incorrect signals, your system can run too long, and that often results in the AC evaporator coil freezing.
Common thermostat problems include:
- Incorrect settings (like leaving the fan set to “on” continuously)
- Battery failures or display glitches
- Improper placement in direct sunlight or near a heat source
Sometimes, a small adjustment or an upgrade to a modern smart thermostat can restore proper system behavior.
5. Watch Out for Blocked Return Vents, Which Can Also Starve Your System of Air
Your system’s return vents pull warm air into the system. If they’re blocked, airflow drops, causing the typical problems that come with poor airflow.
In home layouts that include open living spaces, it’s easy for furniture or curtains to block these vents unintentionally. Always double-check intake vent locations when rearranging or decorating.
How Boerne Homeowners Can Prevent Coil Freezing Year-Round
Preventive care goes a long way. Follow these tips to keep your system efficient:
- Replace filters every 30 to 90 days
- Keep vents and returns open
- Avoid running your AC below 60°F
- Book seasonal routine maintenance with Apollo Air Heating & Cooling
These simple steps can help you avoid frozen coils, expensive breakdowns, and the discomfort of a malfunctioning air conditioner.
Trust Apollo Air Heating & Cooling for Expert Cooling System Repairs in Boerne, Texas
If you’ve noticed signs of trouble, don’t wait. Let Apollo Air Heating & Cooling inspect your system to determine the cause of an AC evaporator coil freezing and perform fast, cost-effective repairs.
We bring over 40 years of HVAC expertise to every home we service. In addition to prompt repairs, call on us for professional routine servicing of your air conditioner before the summer heat sets in.
Contact us to schedule your cooling system inspection today and let our team help you stay cool and worry-free through the toughest days of our Texas summer.