AC Blowing Hot Air? Here’s Why

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Air conditioning unit blowing hot air with red arrows indicating warm airflow, highlighting issues related to AC performance.In the dead of summer, the last thing you want is for your AC to fail. An AC is supposed to blow cool air into a room to keep the heat out.

It may start out working properly, but can change to blowing hot or warm air along the way. An air conditioner blowing hot air can be caused by a few different reasons.

Common Causes of AC Blowing Warm Air

1. Thermostat Settings

The thermostat controls the whole operation so it should be set correctly. It may have changed due to an accidental nudge or bump and this can cause a change in the air temperature.

Simple fix: The thermostat should be set to ‘cool’ instead of ‘warm’ and the fan set to ‘auto’. It may seem like something simple, but it’s easy to forget.

2. Faulty Breaker Switch

The breaker switch cuts off power to the AC unit when required. Whenever the breaker flips off, it cuts off power to the outside unit of the AC, and the inside unit continues to circulate air before it cools.

Simple fix: Flip the breaker switch off and then turn it on again. If it flips off again, that is an indication of a serious electrical problem. That requires a professional; you don’t want to accidentally break the unit.

3. Dirty Air Filter

The purpose of air filters is to keep debris out. With time, the filter gets dirty and blocks airflow to the AC.

Simple fix: One should take it for cleaning or replace it as soon as it gets dirty.

Dirty air filter showing blocked airflow, highlighting the need for cleaning or replacement to maintain AC efficiency.

4. Dirty AC Outside Unit

The outside unit disperses heat from the refrigerant and absorbs heat from the air. Debris can easily clog it. This makes it difficult to disperse heat, and as a result, the AC has trouble cooling the air and leaves the AC blowing hot air.

Simple fix: The outdoor unit requires cleaning at least once a year. A hose used on gentle setting will do the trick, and cleaning frequently will allow only a minimal amount of debris to accumulate. It would yield better results if cleaned when removed and this may require a professional.

In the event that the reason for the AC blowing hot air is leaking refrigerant, a dirty evaporator coil, a broken or disconnected return duct, wiring issues or compressor problems, the only way to fix it well is to get a professional.