WHY IS MY AC BLOWING HOT AIR?

September 19, 2022

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You rely on your air conditioner to keep your home comfortable throughout the summer. Unfortunately, problems can develop that result in it blowing hot air instead of cold into your home. There are several reasons why this can happen.

Incorrect Thermostat Settings

If you feel hot air coming from your vents, the first thing to check is your thermostat. Make sure it didn’t accidentally get set to heat mode instead of cool. Then check that it’s set to your preferred temperature.


Also, check that the fan is set to “AUTO,” not “ON.” If it’s “ON,” the fan runs constantly. This can result in hot air getting blown into your home. By setting the fan to “AUTO,” it only runs when the air conditioner is operating.

Clogged Air Filters

The air filters in your HVAC system capture dust, dirt and other debris as it moves through the ducts. They keep these particles away from your heater and air conditioner while also keeping the air in your home clean.


If you don’t change the air filters, they can become clogged. This restricts airflow and prevents cool air from being circulated throughout your home. It can also cause your HVAC system to work much harder than it should.


How often you need to replace the air filters depends on several factors such as the size of your home, if you have pets, how often the HVAC system operates and whether anyone in your home has allergies or asthma. For most people, the filters should be changed every 2-3 months.

Clogged Condensate Line

When your AC is operating, it reduces the humidity in your home by removing moisture. This condensation is supposed to be carried outside through a condensate line that empties out from the side of your home.


The condensate line can become clogged, which results in a high humidity level and hot air being blown throughout your home. Mold and algae can build up the wet, clogged line. An HVAC technician can clear out the condensate line for you.

Duct Leaks

It’s very common for ductwork to have holes and gaps in it. If there’s a big enough leak, warm air will enter the ductwork and get blown into your home. You should have your ductwork inspected by an HVAC technician every three to five years so leaks can be repaired.

Low Refrigerant

Your AC uses refrigerant to cool the air in your home. If there’s a leak, low refrigerant will result in hot air coming out of your vents. You’ll need a professional to find the leak, repair it and recharge the refrigerant.


The team at AAA Brothers Heating & Air Conditioning in Huntington Beach, PA, can fix this and other AC problems for you.

Dirty Condenser Coil

There’s a condenser coil in the outside AC unit that moves heat from your home and blows it outdoors. Because it’s exposed to the elements, it can get covered in dirt, debris, leaves, grass and more. A layer of grime on the coils will prevent it from doing its job, so hot instead of cold air will be blown into your home.


To prevent this problem, schedule annual preventive maintenance. The technician will clean the condenser coil and other critical parts. You can help by keeping vegetation at least one foot away from the outdoor AC unit.

Failed Compressor

The compressor in your AC system pressurizes and circulates refrigerant. If it breaks, the refrigerant can’t cool the air in your home. You’ll need a technician to diagnose and fix this problem.

Malfunctioning Condenser Fan

There’s a condenser fan in your outdoor AC unit that blows heat away from the coils. When it malfunctions, it triggers a safety mechanism that shuts down your AC system to prevent damage to the fan or motor.

Your AC System is Old

If you take care of your AC system, it should last 15 to 20 years. It will eventually break and either stop working entirely or begin circulating hot air throughout your home. The only way to solve this problem is to have a new AC system installed.


AAA Brothers Heating & Air Conditioning repairs, replaces and tunes-up heaters and air conditioners. We’re also the company to call for water heaters, home generators and indoor air quality solutions. Get in touch today to find out more.



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