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How to Safely Defrost a Frozen A/C Unit

These days temperatures seem warmer than ever in San Antonio, even in fall and winter. For some homeowners, that means turning on the air conditioner now and then. And as long as you’re turning it on, there is always a chance it may freeze up. Do you know why your A/C might freeze up, and what you can do about a frozen A/C unit? Read on for some valuable information.

What to Do When the A/C Freezes Up

The most common reason for an air conditioner freezing up is poor airflow. When the air isn’t flowing properly, the condensation on the evaporator coils can freeze. When that happens, the A/C can’t reach thermostat set points, causing the unit to struggle and work inefficiently. If you suspect the A/C coils are frozen, you should turn the unit off immediately. Turn on the fan and let it run for a couple of hours to help defrost the coils. You can also use a hair dryer on low heat to assist in defrosting the coils. Be sure to clean up any pools of water that have melted around the unit.

Why the A/C May be Freezing Up

Several problems may account for a frozen A/C. Chief among them is a dirty air filter. Dirt on the filter impedes air flow. When the air flow slows down, condensation freezes. Change the filter regularly according to the manufacturer’s recommendations: every three months for times when you don’t use the system much; once a month for summer and winter.

Dirty coils are another common reason for a frozen A/C. If you feel competent to clean the coils, you may do so with a soft brush and mild soap and water. Otherwise, call your HVAC tech.

Low refrigerant charge may also cause an A/C to freeze. Under no circumstances should anyone but a licensed HVAC tech recharge refrigerant. The tech should also probably check for a leak, which if found should be fixed.

To learn more about causes of and fixes for a frozen A/C unit, contact Beyer Boys of San Antonio.

Our goal is to help educate our customers in the greater San Antonio, Texas area about energy and home comfort issues (specific to HVAC systems).