AC Maintenance

5 Things to Stop Your AC Blowing Warm Air

Sometimes your is AC blowing warm air instead of cold, refreshing air. It’s so frustrating, especially when it happens on a hot summer day. But how is that even possible?

Here are five possible answers.

Wrong Thermostat Setting

The thermostat setting is the most simple possible cause for a central air conditioner blowing hot or warm air. Maybe you forgot to switch it to “Cool” mode, and it is still in “Warm” mode. The fan should be in “Auto” mode. Don’t forget to check the temperature setting as well. There is also a chance that your thermostat sensor is not working properly.

Leaked Refrigerant

Your refrigerant may fail to cool down the air if it has even a small leak. A low amount of coolant liquid could also contribute to failure. It is not easy to directly check on your refrigerant because it is located inside the unit. However, there are some signs of leaked refrigerant, such as:

  • Your outside unit is iced/frozen
  • There are hissing or bubbling noises coming from your AC unit
  • Your air conditioner blows hot air in the afternoon but colder air at night

A refrigerant leak is not something you can fix yourself. You need to hire a licensed HVAC repairman to get the job done.

Disconnected or Leaky Air Ducts

Another common cause of a central air conditioner unit blowing out warm air is an air duct problem. Cold air leaks if there is a crack or hole in the air ducts. Ultimately, only a small amount of cold air will enter your room. Meanwhile, if one of your air duct joints is disconnected, the cold air won’t flow. Thus, only warmer air will make it to your room. Take a look at your ducts, if possible. If this is not possible, then you should get professional help.

Dirty Condenser

Do you perform regular maintenance on your home HVAC system? If not, maybe your central air conditioner is blowing out hot air because your condenser is dirty. Without regular maintenance, dirt, and debris build up around your condenser. As a result, your condenser won’t be able to remove the heat from your home. Therefore, it will flow back into your house.

Electrical Issue

Electrical problems with the outdoor unit of a central air conditioner may prevent it from cooling the air. Yet, your indoor unit will still do its job of blowing out whatever air it has. Thus, it will blow out warmer air that the outdoor unit failed to cool. Try resetting your circuit breaker or fuse. If the problem persists, you need professional help from a licensed electrician.

Nobody wants hot air blown out of their central AC unit. But at least now you know what to check for if this happens.

East Coast Mechanical - ECM Air Conditioning

Share
Published by
East Coast Mechanical - ECM Air Conditioning

Recent Posts

Unveiling 2025’s Best Central Air Conditioners

Choosing the right air conditioner brand can feel a bit like picking out a car—you…

8 months ago

Simple Tips to Extend the Life of Your Air Conditioner

Have you ever wondered how long your heating or cooling system will keep running before…

8 months ago

Troubleshooting AC Short-Cycling

Air conditioning isn't just about keeping cool—it's about comfort, efficiency, and even health. But what…

8 months ago

Professional Water Heater Installation Matters for Your Home

When it comes to keeping your home comfortable and functional, a reliable water heater plays…

8 months ago

How Your AC System Can Help Combat Indoor Air Pollution

When it comes to your home, air quality takes center stage. Your air conditioning (AC)…

8 months ago

Key AC Repair Parts to Keep Your System Running

When it comes to keeping your home cool and comfortable, few systems are as efficient…

9 months ago