Why Is My Air Condition Blowing Hot Air?

ac blowing hot air

Summer is here, and so is the blistering heat. After spending time under the sun, whether barbequing or hanging by the pool, the last thing you want to experience when you step inside is an overheated house.

We rely on our air conditioning unit to bring much-needed relief from the heat and humidity, but what happens when our AC stops funneling in cool air and instead blows hot air into our home. There are a few different issues that could be causing your home air conditioning unit to blow hot air instead of cool. While some of these issues can be solved on your own, more often than not, you will need an experienced HVAC technician to fix the problem.

When warm air starts coming through your air conditioning vents, you can be prepared and know exactly what your next step should be. Read on to learn some common reasons why your AC may be blowing hot air and actions you need to take to get your home air conditioning unit back on track.

Why your AC unit might be blowing hot air

Incorrectly Set Thermostat

The first thing you should be looking at when you notice warm air coming through your vents is your thermostat settings. Sometimes a little bump against your thermostat can alter the settings and make your heating and air conditioning unit do the exact opposite of what you want.

First, if you notice that your thermostat is set to HEAT, switch it over to DISPLAY COOL, and see if your AC begins to blow cool air. If the fan is set to AUTO, it will continuously blow air through vents, even when the cooling cycle is not running. This will cause you to feel warm air coming through vents.

ac blowing hot air

If the steps above do not help cool down your home, and you still think your thermostat is the issue, try replacing the batteries. A thermostat with low batteries will often lose functionality, which can cause problems when relaying the desired temperature to your HVAC system.

Solution: Check your thermostat before giving Brackett Heating, Air & Plumbing a call!

Dirty or Frozen Evaporator Coils

Dirty evaporator coils may be the cause of hot air coming through vents in your home. The primary purpose of the evaporator coils is to cool the refrigerant so that it can absorb the heat from your home. Without an annual maintenance check, your evaporator coils can get neglected and develop a build-up of dirt and debris. When this build-up happens, it may cause a restriction in airflow, leading to your air conditioner blowing hot air instead of cool.

Another issue you may encounter with your evaporator coils starts with your air filter. A dirty air filter can cause your evaporator coils to freeze, hindering the flow of cool air into your home.

Solution: When dealing with dirty evaporator coils, it’s best to call Brackett. We will ensure the coils are properly cleaned and ready to help produce cool air for your home.

If you notice your evaporator coils are frozen, inspect your air filter; a dirty or clogged filter should be changed. Turn off your unit, replace your air filter, and wait for the evaporator coils to dethaw before turning your unit back on.

Call Brackett if your evaporator coils are frozen, but your air filter does not need to be replaced. This could indicate a refrigerant leak.

Low Refrigerant Levels

One of the leading causes of hot air coming through vents is low refrigerant levels. Refrigerant is a necessary component in maintaining the performance of your air conditioning unit. If you have low refrigerant levels, it could be caused by a leak. A refrigerant leak will ultimately cause your AC unit to stop producing cool air for your home. The air conditioner will continue to run and constantly blow warm air as it tries to reach your desired temperature.

An easy way to identify a refrigerant leak is by checking your evaporator coils. If you notice that your evaporator coils are frozen, that could signify a refrigerant leak.

It’s important to note that leaking refrigerant poses a significant danger to your health and safety, and if it is not fixed promptly, it could cause further damage to your unit. This issue should be fixed right away by a highly qualified technician.

Solution: Do not try to fix this issue yourself. Call one of our experienced Brackett Heating, Air & Plumbing technicians to inspect your air conditioning unit. To prevent this issue in the future, make sure you are scheduling regular maintenance checks with our team.

Outdoor Unit Lost Power

HVAC units use a significant amount of power to run. Sometimes, if the outdoor unit uses too much power, it can cause issues such as tripping a circuit breaker or blowing a fuse. When this happens, your outdoor unit will not be able to cool the air; therefore, your indoor unit continues to blow warm air throughout your home.

Solution: Oftentimes, circuit breakers will trip as a safety precaution when there is too much power demand. Locate your circuit panel and flip the breaker for your outdoor unit off and back on. If your breaker keeps tripping, call our team to investigate this issue.

breaker switch

If you did not trip the circuit breaker, locate your fuse box and check for a blown fuse. A homeowner should not fix a blown fuse; call a qualified electrician to help replace the fuse.

Outdoor Unit Needs to be Cleaned

If you’ve noticed that your HVAC system isn’t working as well as it should, your outdoor unit may be obstructed.

When your outdoor unit has overgrown shrubs, fallen branches, leaves, or dirt blocking it, this can sometimes cause your unit to work harder than it needs to. Ultimately, this can cause your outdoor unit to overheat.

air conditioner unit blowing hot air


Solution: Luckily, this issue is an easy fix for homeowners! Clear away any debris from the surrounding area of your outdoor unit. Make sure you continue to clear away any debris that has fallen around or onto your unit throughout the year to help maintain the efficiency of your HVAC system.

We understand that the last thing any homeowner wants is to be faced with a home air conditioning unit that doesn’t produce their desired air quality, especially during the summer. However, if that time comes, it’s essential to know what might be causing it and the steps you can take to fix the issue quickly.

Know that you can always rely on the Brackett Heating, Air & Plumbing professionals to help you maintain comfort in your home year-round!