Nothing makes you appreciate your air conditioner like a hot summer day. While it feels good to catch a few rays and soak in some Vitamin D, it’s even nicer to walk into your cool house, temperature-controlled to perfection. 

That is until your AC unit fails… then you find yourself sweltering in the heat, desperately looking for a solution. 

What causes AC failure? Keep reading to find out the six leading culprits. 

Common Causes of Summer Air Conditioning Failure

During the summertime, there are a few leading causes behind AC failure. Once you’re familiar with them, you can pinpoint the issue and schedule a speedy air conditioning repair. 

#1 Dirty Air Filters

The most common cause of AC failure is dirty air filters. When your air filters are clogged with excessive particulate build-up, they prevent air from moving around freely. 

In turn, you may notice the following problems:

  • The inability to cool your home properly
  • Excessive energy consumption
  • Poor air quality 

Fortunately, the solution is super simple—just change out your air filters. Most filters only cost around $15 for a set of three. Before you purchase any, make sure that they’re compatible with your HVAC system. 

#2 A Refrigerant Leak 

Refrigerant is another crucial element of your AC system. It’s responsible for ensuring that hot air leaves your home. Without it, your home’s temperature can’t be properly controlled.

During the summer months, your AC system operates on overdrive to keep your home cool. In turn, it uses more refrigerant than normal. The tubes that carry this refrigerant are placed under great pressure, and over time, this can cause them to crack. If this happens, your system’s refrigerant will leak out, leaving your house hot and miserable. 

You can spot a refrigerant leakage by the presence of liquid near your outdoor condenser coil. If you think you’re experiencing a refrigerant leak, schedule an air conditioner repair with a licensed technician ASAP. Refrigerant is a toxic substance, so you don’t want to mess with it on your own. 

#3 Frozen Evaporator Coils

Refrigerant works in conjunction with another important HVAC system feature: the evaporator coils. These coils transform refrigerant liquid into gas, which helps remove hot air from your home. However, if they get too cold, they can freeze and stop functioning correctly. In turn, your AC may fail.

The causes of frozen coils are:

  • A refrigerant leak 
  • Dirty air filters
  • A system blockage

Once you notice an icy evaporator coil, contact your HVAC team immediately. If it goes unaddressed for too long, your entire AC system could get damaged, requiring even costlier repairs.

#4 A Faulty Thermostat

Your AC’s thermostat shows you what the temperature is currently and allows you to adjust it as needed. However, if it’s improperly calibrated, your AC may turn on and off frequently. This phenomenon is known as “short-cycling.”

Short-cycling has many negative consequences, including:

  • Decreasing the longevity of your AC unit
  • Wasting energy
  • Increasing your electricity bill
  • Making your home either too hot or too cold

If you believe your thermostat is faulty, call an HVAC specialist to take a look at it. They may be able to repair it. Otherwise, you’ll probably need to purchase a replacement.

#5 A Faulty Blower Fan

Your AC’s indoor fan, also known as the blower, is responsible for blowing the cool air out of the system and into your home. If it’s not working properly, all of the cool air will remain trapped in the system. 

Some reasons for a faulty fan include:

  • An internal obstruction
  • A broken fan motor
  • Long term wear and tear
  • A dirty AC system

Since so many things could be at play, you’ll want an HVAC specialist to check out the blower and see what’s causing the problem.

#6 Neglecting Maintenance

The last common cause of AC failure is neglecting regular maintenance. AC systems run best when they’re properly maintained. In fact, staying up-to-date with your maintenance prevents most of the problems previously mentioned.

It’s a good idea to schedule maintenance with an air conditioning replacement service at least twice a year. During this time, your HVAC specialist will:

  • Inspect the entire system
  • Clean your coils
  • Replace your air filters

By preventing problems before they occur, you’ll never have to go without AC during the summertime heat.

Simpson Sheet Metal Can Save the Day

If you’re experiencing electrical issues with your air conditioning unit, reach out to the HVAC professionals at Simpson Sheet Metal. With their expertise in AC unit installation, repairs, and maintenance, they can take care of any issue you’re experiencing. 

By partnering with Simpson Sheet Metal, you’ll enjoy a free in-home consultation. All of Simpson Sheet Metal’s labor and equipment is under warranty, so you can trust their work. Furthermore, Simpson Sheet Metal offers convenient financing options to make your much-needed AC a little more affordable in the hot summer months.


U.S. Department of Energy. Energy Saver 101 Infographic: Home Cooling.

EPA. Refrigerant Safety.