Why is My AC Blowing Warm Air? 5 Common Causes and Simple Fixes

Are you wondering why your AC is blowing warm air?

Obviously, it is a problem if your air conditioner is blowing hot or warm air, considering its purpose is to cool your house, not heat it! When your unit blows warm air, the issue can range from simple to more serious. Changing a filter and adjusting some settings on your AC unit could fix the issue. However, you might also have a serious problem that needs to be addressed.

Either way, our goal here at Top Shelf Heating & Cooling of The Treasure Valley is to provide you with the five most common reasons why an AC unit blows warm air and what to do if you find yourself in this predicament!

The 5 Common Causes of an Air Conditioner Blowing Warm or Hot Air:

The five most common causes of your potential air conditioning problem (blowing warm air) are:

1. Dirty air filters
2. Refrigerant evaporator coil issues or a refrigerant leak
3. Low refrigerant levels
4. Clogged condenser coils
5. Malfunctioning compressor

Now, we understand if your AC is blowing warm air, you are looking to diagnose and quickly address the problem at hand. While some of the above might exceed the scope at which you can fix, it our goal to break each down and help you understand ways to prevent these issues before they ever occur and know when to seek out professional help!

1. Clogged Air Filters

A clogged or dirty air filter can reduce airflow and cause your air conditioner to blow warm or even hot air. By regularly changing your air filter, you can prevent this problem from happening, and it is vital to keep in mind that a dirty air filter can reduce the lifespan of your AC unit. By cleaning or replacing your air filter, you can decrease energy bill costs and also prevent your AC unit from blowing warm air. If changing your filters doesn’t fix the issue, chances are you may have something else going on!

2. Evaporator Coil Issues

Refrigerant evaporator coil malfunctions can prevent the air conditioner from cooling properly.

• Check the evaporator coils for frost or ice buildup.
• Verify that the coils are not frozen or clogged.
• Use a heat gun or hair dryer to thaw frozen coils.
• Give us a call to schedule a repair if the issue persists.

3. Low Refrigerant

A typical reason your air conditioner isn’t functioning correctly is because of low refrigerant levels. Refrigerant leaks can occur for a variety of reasons including old hoses, rusted or punctured evaporator, or other issues. In the case of refrigerant issues, a professional is required to fix a refrigerant leak and help you recharge the system. Be sure to first have them diagnose the link before recharging your air conditioner.

Keep in mind that regular maintenance can help detect refrigerant leaks early on before your unit breaks or blows hot air. All HVAC companies recommend you schedule an AC maintenance check each spring before you need to use your air conditioner.

4. Clogged condenser coils

If your AC unit is blowing warm air and you have confirmed that the first three on this list aren’t the problem, then the next step is to assess your condenser coils. Dirty condenser coils are problematic because they are paramount in releasing heat from the house into the atmosphere.

Clogged condenser coils can impede effective cooling and cause the air conditioner to blow warm or hot air. In the photo above, lint, plants, mildew, and other debris are clogging this unit and impacting the condenser coils.

5. Malfunctioning Compressor

A restricted or malfunctioning compressor can cause your air conditioner to blow warm or hot air and the most common sign of this is noise! Be sure to listen for unusual noises from the air conditioning unit, and you can check for signs of a failing compressor, such as reduced airflow or even increased energy bills.

If you need help, feel free to reach out to us to schedule a repair if the issue persists.

AC Troubleshooting Tips

Before you call an HVAC company, there are simple troubleshooting tips that can help you address your system blowing hot air or even no air!

Step 1:

First, check your thermostat to ensure it’s set to “cool” or “auto” and not just circulating warm air. This will dehumidify the indoor air, and thus, you will have cold air again!

Checking if the fan is running and circulating warm air throughout the home and adjusting the thermostat settings as needed to can resolve the issue. We have gone to many homes to help with their AC only to see their systems settings were incorrect.

Step 2:

Somtimes electrical issues can prevent the air conditioner from cooling properly and cause it to blow hot air. Something as simple as a tripped breaker or electrical surge can cause your air conditioner to stop working. In the event that your outdoor unit lost power, this can cause the air conditioner to blow warm or hot air.

Here is how to check for power issues:

• Check the circuit breaker panel for a tripped switch.
• Ensure the outdoor unit is receiving power and hasn’t been turned off by a technician.
• Reset the breaker or replace the fuse to restore power to the air conditioner.
• Check the power supply to the outdoor unit to ensure it’s working properly.
• Inspect for any obstructions around the outdoor unit that could be blocking airflow such as plants, mildew, or debris.

If you check the power and adjust your thermostat settings, chances are you have an actual issue that requires the attention of an HVAC company. Here at Top Shelf Heating, we have professionals ready to solve your cooling needs 24/7/365. Simply reach out here:

Maintenance and Repair Issues

Similar to a car, regular maintenance can help prevent issues with your air conditioner, ensuring it blows cool air, not hot. While regular maintenance can include changing air filters, we recommend you schedule a maintenance check every year to ensure that your air conditioner is working correctly before the hot summer months arrive.

Regular maintenance can help prevent issues with the air conditioner, such as a malfunctioning compressor, low refrigerant, a refrigerant leak, or frozen evaporator coils. Your HVAC system will last longer and perform better when you have regular maintenance, and we have trusted HVAC professionals ready to help you!

Schedule a maintenance time fast below! ⬇️

Knowing When to Seek Professional Help

When your home is hot and the AC is blowing warm air, hopefully you can troubleshoot the issue quickly. However, if none of the troubleshooting steps work, it’s likely that the issue is more complex and requires the expertise of an HVAC professional like Top Shelf Heating & Cooling.

If your air conditioner isn’t functioning properly, you will quickly notice by the lack of cool air in your indoor area. We recommend that if you have an issue unrelated to the power or thermostat, don’t hesitate to have routine and emergency repairs done before the problem gets bigger. A leak or dirty coil is a simple fix; however, if it is left unchecked, it could grow into a bigger issue!

We always recommend that you first contact an HVAC professional to diagnose and fix the issue before trying to do it on your own if changing the filter and checking the power doesn’t work. Problems like low refrigerant or evaporator coil problems are not DIY issues. In order to get your air conditioner blowing cool air quickly, you need the help of a reputable HVAC company!

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