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Blogs from May, 2021

Why Is My AC Blowing Warm Air? Seven Common Reasons It's Heating Up

inside of hot air balloon

inside of hot air balloon

Why Is My AC Blowing Warm Air? 

What the heck has happened? All of a sudden your AC is blowing enough warm air to dry your hair. As the day goes on, it feels like your AC is blowing enough hot air to fuel a balloon.  What could possibly have gone wrong? 

Here are seven common reasons that your AC is heating up: 

1) Thermostat Problems:

First things first. Check to make sure your thermostat is set correctly. You wouldn't believe the number of times that human error is involved in the temperature settings of your AC.  

  • Make sure that the setting is on Cool and hasn't been accidentally moved to Heat. 
  • Check that the blower fan is on "Auto" and not "ON."  If it's "ON," that means that the fan on your system will run continually, all the time. When the system is not cooling, the fan will continue to blow air, even if it's warm. 
  • If you have a smart or wifi thermostat, make sure that a temperature setting has not been moved into a "scheduled" setting. 
  • If your thermostat is old, it may need to be recalibrated or replaced.

2) Dirty Air Filters:

Air conditioners work by pushing cold air through air ducts built into your home. Filters are placed on your central air system so that dirt, dust, and pollen can be captured and kept from blowing onto you and into your system. 

If those filters are dirty, cool air cannot get through. 

  • Know when your AC filters were last changed. (Mark them with a marker or sticker.)
  • Most HVAC professionals recommend replacing filters every 30-45 days, depending on the kind of filters you use, the size of home you have, whether or not you have allergies or respiratory problems, and if there are pets in the home.  
  • You can reduce your AC costs by replacing your filters on a regular basis. 

3) Electrical Problems:

It's possible that electricity isn't getting to the outside unit. Check your breaker box to make sure that a fuse hasn't been flipped off or blown. 

 4) Blocked Circulation

You know those pretty shrubs you put around your outside unit to camouflage it?

  • Check to make sure bushes and shrubbery haven't grown and gotten too close to the unit, blocking the air circulation. 
  • If you have built a small fence or decorative panel around the outside unit, make sure there is plenty of space between it and the AC unit for air to circulate.
  • Remove any items, dirt, or debris that may be resting against the AC unit. 

5) Issues with Ductwork  

It is possible that your cold air is leaking out from a problem with the ductwork and the only thing that's getting through is warm air. 

  • Your ductwork is something you don't see because it's inside your walls and ceilings. You may not realize there's a problem.
  • Ducts can leak if animals, (think mice, raccoons, bats) or birds have interfered with them.
  • Storm or roof damage can cause structural problems with ductwork. 
  • Incorrect installation or sloppy work might create a gap in ductwork. 

A trained HVAC professional can check the hidden workings of your AC system for problems with ducts if your ac is blowing warm air. 

6)  Frozen Coils  

Evaporator coils can freeze up when not enough warm air can circulate around the cold coils to keep them from icing up. A frozen AC condenser can also be caused by too little refrigerant or plugged air filter. Ice on the coils can also be caused by a build-up of dirt on the inside coil or blower assembly, that blocks the airflow. 

No matter what causes the ice, the results are that your cool air doesn't flow properly causing your AC to blow warm air. If left untreated, the freezing can cause expensive damage to major components of your AC system.

7) Leaking Refrigerant

If your system doesn't have the right amount of refrigerant, the air can't be adequately cooled. It may be that your system has an undetected refrigerant leak, something you need a licensed and certified HVAC technician to test.  

If you observe any of these signs, you might have a refrigerant leak: 

  • An unexplained uptick in your electricity bill
  • Frozen coils 
  • A faint hissing sound 

The Simplest Way to Stop Your AC from Blowing Warm Air

Call us at ServiceOne Air Conditioning and Plumbing. We have a staff of trained and talented HVAC techs and plumbers to help you. 

We want to make sure your ac stops blowing warm air.  You probably don't need it to dry your hair or fill a hot air balloon, anyway. 

Call us. We'll put you in your comfort zone, whatever temperature that may be!



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