Why is my AC blowing hot air in my house?

It is hot out there, and it is getting hotter. Air conditioning used to be a luxury, but it is now essential to our comfort and health, especially in central Virginia. What happens when your air conditioner stops cooling your home and starts blowing hot air instead? Read on to learn more about the causes of your AC blowing warm air, tips to troubleshoot any issues, and ways to maintain your AC for many years of comfortable cooling.

AC Blowing Warm Air

Why is my AC blowing hot air in my house?

 No one wants to get home and open the door to a hot and humid house. You check the thermostat to see if you set it at the right temperature. You put your hand over the vents to see if the air blowing is cool or warm. You conclude that something is definitely wrong, and you wonder why it is happening. You thought the AC unit still had lots of life left in it. Before assuming the worst, let’s look at the specific reasons why your central air is blowing warm air. Your AC unit blowing hot air outside also might be a concern. Your air conditioner components outside and inside must work together to properly keep your home cool.

Is it the unit itself or some other reason my AC is blowing warm air?

 Reasons an AC might blow warm air:

Refrigerant issues. Low refrigerant levels or a refrigerant leak can lead to your AC blowing warm air. If this is the case, Mode Comfort & Air Quality can professionally inspect the system, locate any leaks and repair them when possible, and recharge the refrigerant if needed.

Faulty compressor. The compressor is responsible for circulating refrigerant through the AC system. When your compressor malfunctions or stops working completely, it cannot provide the cool air you need. This is a complex issue that requires professional assistance, so rely on Mode Comfort & Air Quality to diagnose a compressor issue.

Dirty evaporator coils. These coils are located in the indoor air handler unit and play a vital role in the cooling process. This is where hot air is absorbed and cooled through refrigeration. If these coils become clogged or dirty, it restricts their ability to cool air efficiently. Frozen evaporator coils are often the culprit, as well. 

-Dirty or damaged condenser coils. The condenser coils are located in the outdoor unit. These coils enable the system to remove heat from the refrigerant that was absorbed by the evaporator coils. If these coils are dirty, obstructed (such as by a fence around the outdoor unit), or damaged, this can cause major issues. 

 -Capacitor failure. If your capacitor has died, your unit may blow warm air. Luckily, this is an easy fix.

Potential causes of your Air Conditioner blowing warm air other than the unit itself include:

cooling mode

Thermostat settings or malfunctions. It would be great for homeowners if the only reason the AC is blowing hot air is because the thermostat is set to heat instead of cooling mode. It could also be that the temperature itself is set to higher than the outside temperature so that the thermostat won’t turn on your HVAC system. Your thermostat could be broken or simply need batteries if not hard-wired. Your expert technicians at Mode Comfort & Air Quality perform thorough testing and inspection of all components. You won’t be charged for any unnecessary repairs. 

Airflow restrictions. Check if any obstructions are blocking the airflow from the AC vents, such as furniture, curtains, or other objects. Restricted airflow can prevent the cool air from circulating effectively. If your AC is blowing cold air but the house is still hot, even something as simple as opening closed vents can help get your home cool. You also need to make sure the airflow around the outside AC unit is not obstructed. Debris and overgrown landscaping can cause your AC unit to work harder and overheat. Your outside AC unit needs breathing room to operate efficiently.

Duct leaks. If there is a large leak in your home’s ductwork, cool air may not make it out of the vents into your living areas. Ducts within your home are responsible for delivering the cooled air from the HVAC to the rooms of your dwelling. When there is a leak, warm air mixes with the cold and warmer than normal air is what you feel coming from the vents. Leave any ductwork inspection to the professionals at Mode Comfort & Air Quality.

Dirty air filters. Replacing your air filter as recommended should be the first lesson in Homeownership 101. A dirty or clogged air filter can restrict airflow and reduce the cooling capacity of your AC system. Check the air filters and clean or replace them if necessary. Depending on the type of filter you have in your home, clean or replace filters every 3 months unless you have a lot of dust and pet dander, which requires more frequent attention. 

Electrical problems. Electrical issues, such as a tripped circuit breaker or a blown fuse, can disrupt the AC’s cooling process. Check the electrical panel and reset any tripped breakers or replace blown fuses. 

How can I troubleshoot the problem of my AC blowing hot air?

  1. Check the thermostat. It should be in cooling mode with a temperature set lower than the current room temperature. Change the batteries if necessary.
  2. Check the air filter and change or clean if required.
  3. Make sure your air vents and registers are open and unobstructed.
  4. Verify your electrical power to the AC is on and operable. A tripped breaker is an easy fix to an AC that blows hot air.
  5. Clean the outdoor unit. Hose it down after removing any obstructions that can impact the cooling efficiency.
  6. Call the professionals at Mode Comfort & Air Quality. If you’ve performed the basic troubleshooting steps and the AC problem persists, one call to Mode Comfort & Air Quality will give you peace of mind that we have the expertise and tools to diagnose and repair complex AC issues safely. We can also quickly replace your AC if necessary.

What steps can I take to prevent my AC from blowing warm air in the future?

 The simplest and most cost-efficient way to prevent your air conditioner from blowing hot air is preventative maintenance. This goes beyond changing the air filter. Consider professional AC tune-ups from Mode Comfort & Air Quality, especially if your unit is older. Our quality techs inspect your AC system thoroughly, clean the coil to prevent freezing, clean the condensate line, and test coolant pressure and levels. Schedule your AC tune-up in the spring before it needs to work overtime. You don’t want to regret not calling us sooner when you find your air conditioner blowing hot air on a 90-degree day. Consider joining our Fan Club preventative maintenance program for regular check-ups.

Common FAQs for AC Blowing Warm Air

Why is my AC running all the time but not cooling?

You may find that your home is not cooling down, but the AC blowing warm air is not the problem. Start with looking at simple causes. Are your windows open? Close them so hot air cannot get in and cool air cannot escape. Is your oven on? If you’ve been baking all day, the air in your kitchen area will be warmer than normal. Are children running in and out the door all day, perhaps leaving the door open? Do you have construction happening in your home? Other issues can include insufficient insulation. Inadequate insulation in your home can cause cool air to escape and hot air to infiltrate, leading to prolonged AC operation without proper cooling. Insulating your home adequately, especially in attics, walls, and windows, can help improve cooling efficiency.

Consider the size of your current AC unit. If your air conditioner is too large or too small for the space it’s cooling, it can result in inefficient operation. An oversized unit cools the space quickly but may not run long enough to dehumidify, while an undersized unit may struggle to cool the area adequately. Many homeowners don’t consider the size of their AC unit as the reason why their AC is blowing hot air. Mode Comfort & Air Quality will recommend just the right sized unit to operate to peak efficiency in your home.

Can I fix my AC blowing out hot air on my own?

DIY air conditioning repair is not recommended. HVAC is a big investment for homeowners, and the comfort of your family is very important. You can follow the troubleshooting guidelines above if the AC is blowing hot air on cool, but skip the “how to fix AC blowing hot air” videos on YouTube and go straight to the telephone and call Mode Comfort & Air Quality when you want to answer the question of why is my AC blowing warm air.

When my AC is blowing hot air, who can I call to fix it right the first time?

 You must hire the right contractor to repair your AC unit blowing warm air or replace it when your AC unit is blowing hot air. In Virginia, Mode Comfort & Air Quality is the right choice. We fill every need from basic HVAC maintenance to complex AC repairs and total system replacement. For AC repair, Chesterfield residents count on Mode Comfort & Air Quality. For AC repair, Richmond residents count on Mode Comfort & Air Quality. For AC repair. Midlothian residents count on Mode Comfort & Air Quality. Don’t get hot over a broken AC, call or text Mode Comfort & Air Quality today at (804) 481-6633.