Why is my AC blowing hot air?

Air conditioners outside home
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May 23, 2018
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With dozens of parts that must function properly in order to efficiently cool your home, it’s no wonder that when one part goes out, your whole AC unit could malfunction causing it to blow warm or even hot air. Before you literally start sweating, check out the most common causes for this that you may be able to diagnose and even fix on your own.

1. Frozen AC unit

It can come as a surprise, but air conditioners can actually freeze. This is one of the most common causes of air conditioners blowing warm or hot air because the inside has frozen into a block of ice. The reason for the warm air blowing out is because the frozen part is the evaporator coil, which can block the cool air flowing into your home. Instead, the motor’s heat gives you a warm air flow, so as long as the fan is not frozen, all is well. To fix this issue try turning it off and letting it thaw. After about an hour or two, it should be safe to turn back on. If it freezes again, you should contact an AC repair company, such as Crystal Heating and Cooling, to take a look at it.

2. Thermostat settings

As silly as it seems, it’s actually quite common for homeowners to forget that they have to switch their thermostat from “warm” to “cool”. It’s important to also make sure the unit’s temperature is not set too high on auto. Make a note to yourself before the warmer months comes to turn your AC unit on “cool” mode. If you check your thermostat and the mode is set correctly, check the temperature and adjust it accordingly.

3. Blown breaker switch

As with any appliance that requires power, your AC unit has a power supply which also has an on/off switch that can be tripped by a bad breaker. Without power, the unit simply won’t turn on. Breakers often flip off when there is a power overload as a safety precaution. To prevent this from happening, consult an electrician to ensure your breaker can handle the current draw of your unit. The fix for this issue is quite simple. Just flip the breaker back to the “on” position. If that does not work, contact an electrician.

4. Dirty air filters

When was the last time you changed or cleaned the air filter in your AC unit? Most people never do until something goes wrong and it’s too late. Air filters get dirty and can block that clean cool air from entering your home. This blockage won’t clear up until you or a technician take it out and replace it. Although the filter alone won’t cause warm air to blow, it will contribute to the problem and reduce cooling effectiveness significantly.

If you have checked for all of the causes mentioned above and you’re still finding that your AC unit is blowing warm air, and you’re in the Brant Country area, give Crystal Heating and Cooling a call and we will have you back up and running in no time. It’s no sweat.