Why does my ac keep freezing up?

It almost seems counter-intuitive that an air conditioner could freeze over, especially during the summer months out here in Las Vegas, where the dust and heat are extreme. Right when you need your unit the most, it malfunctions for reasons that you may not initially understand, leaving you with a frozen air conditioner and a house that’s uncomfortably warm.

Las Vegas Resident With Frozen Air Conditioner, blocked vents, or Other AC Problems?

Contact Us Today for AC Repair or AC Replacement. Our team can answer any questions you have about various AC issues.

What Causes an AC to Freeze Up?

There are a variety of different problems that could cause your HVAC system to freeze. The type of issue could range from a dirty filter to low refrigerant:

Your Thermostat Could Simply Be Malfunctioning

If your thermostat is malfunctioning, it may be working your air conditioner too hard. As your unit runs too long, through ductwork and vents, it’s easy for the AC coils to freeze, primarily if there is insufficient insulation to keep the heat out.

You Have Air Flow Problems

The coil on the air conditioning system needs proper airflow to prevent the condensation from freezing. Many times, a frozen AC unit is due to airflow problems that have kept warm air from controlling the temperature of this condensation, potentially because of blocked vents.

The simplest possible solution to this problem is changing your dirty filter. Dirty air filters can lead to airflow problems contributing to the buildup of humidity, which in turn can cause the AC to freeze. Be sure to change dirty air filters regularly, and keep in mind that your air conditioner freezing from this issue may signal that you need regular AC maintenance.

However, you may have a broken fan or a malfunctioning compressor. Both could also be potential causes of your airflow problems as, even if your air filters are clean, there is no mechanism to effectively push the air through the system.

You’re Leaking Freon/Coolant

If the airflow isn’t the problem, it’s possible that there’s a refrigerant leak. A leak can cause low refrigerant pressure that mitigates its functionality in absorbing heat and thus causing the coil to freeze over. A temporary solution is to add more refrigerant to the system, but ultimately, you should begin thinking about contacting a contractor to repair or replace your AC system.

You May Have a Blocked Condensate Line

Condensate lines help drain moisture buildup, but if they become clogged (especially near the evaporator coil), the water and coils could freeze. This mainly happens with a condenser that isn’t adequately handling moisture.

What to Do When Your AC Unit Freezes Up: How Do You Unfreeze an Air Conditioner?

So your air conditioner has frozen, and you don’t want to call an AC company prematurely. What do you do? Here are the steps you can take to unfreeze an air conditioner and ensure that it’s not a simple, easily fixed problem that’s causing your unit to freeze up.

  • Shut the unit off
  • Find and clean up any water damage
  • Wait for the unit to defrost and the ice to melt (Never CHIP off the ice as you could damage essential components)
  • After an hour (possibly more), run just the fan to get some air flowing through the system
  • Check the air filters to ensure they’re not in need of replacing

Why Does My AC Keep Freezing?

Okay, so you followed the steps above, but your air conditioning unit does it again a few days later. And again a few days after that. Obviously, something is going wrong to warrant this ongoing issue, and you’ll want to fix your frozen air conditioner permanently.

Be sure to pay attention when your AC comes back up to see if it is constantly running without ever turning off (which could indicate the issue with your thermostat). Otherwise, the best way to troubleshoot is to call an HVAC contractor. Air conditioners have many moving parts and, unfortunately, many potential points of failure.

If the AC continues to freeze multiple times after you’ve replaced the air filters and ruled out the thermostat, there is undoubtedly an issue with either the airflow in your home or a component failure that’s causing the coils to freeze. These issues go beyond what the typical homeowner can do, so it’s best to contact a professional HVAC company.