What to Do When You Find Your AC Blowing Out Hot Air

June 10, 2021

When your AC is blowing out cool air, it's a fascinating machine that keeps your home comfortable. When you find your AC blowing out hot air, that raises an eyebrow, and it becomes a perplexing contraption inside a metal box that you're not sure how to deal with. In reality, an AC blowing out hot air is a common problem with several possible causes. You may be able to resolve some of these issues yourself. Other reasons for hot air blowing from the air-supply vents are more complex and require the trained eye and tools of your HVAC technician. Keep reading to learn what to know and do about your AC blowing out hot air.

Wrong Thermostat Setting

Before you work up a sweat, check the thermostat settings. Your thermostat should be set to "Cool" and "Auto" for cooling mode. The "Auto" setting, rather than the "On" setting, means your AC blower will turn off and on with the cooling system. It won't run when the AC is not cooling return air, which prevents AC blowing out hot air.

Ice on the Evaporator Coil

The AC unit cools your home by removing heat from the return airflow and blowing the chilled air through the air vents. The device that chills hot return air is the evaporator coil, which contains very cold refrigerant. If there isn't enough hot air blowing across the evaporator, ice will build up and encapsulate the device. This means hot return air won't be chilled and will simply return to your home through the air vents.

Compressor Going Bad

The compressor is sometimes called the "heart" of the AC system. The compressor prepares and pumps refrigerant between the condenser coil located outside your home and the evaporator coil located inside your home.

As cold refrigerant vapor enters the compressor, the refrigerant gas is compressed into a hot liquid. The hot refrigerant enters the condenser coil, and heat energy is released. If the compressor is failing, the refrigerant won't be able to remove heat from your home and release it outside.

If you're having problems with the AC blowing out hot air in your home, please contact Aggressive Mechanical Contractors.