When your air conditioner constantly shuts down unexpectedly or repeatedly trips the circuit breaker, it's probably trying to tell you it's too hot. It may seem ironic that a machine designed to keep spaces cool would overheat, but here are three reasons why it happens and what you can do to fix the problem.

It's Dirty

The most common reason air conditioners overheat is that they're dirty. Dust and other contaminants get inside the appliance, creating a film of grime that traps heat and impairs functionality. Air filters are the biggest offenders in this area. When they become clogged with dirt, they make it more difficult for air to pass through which, in turn, forces the air conditioners to work harder than they need to, leading to overheating.

The evaporator and condenser coils are also prone to getting dirty. In this case, the dirt covering the parts traps heat, making the air conditioner run hotter than it normally would, which, again, makes it tough for your machine to work efficiently and can actually lead to it breaking down before it's time.

Luckily, this is an easy fix. Be sure to change your air filters on a regular basis according to the manufacturer's recommendations. Air conditioner coils should be cleaned at least once per year, especially after major environmental events that expose your machine to more debris than usual (e.g., dust storms, flooding). If your A/C is located outside, keep the area surrounding it clear of vegetation, and be careful when cutting the grass around the machine to avoid sending clippings inside that could clog it.

It's Old or Broken

Overheating problems can also be caused by age. No matter how well you care for your air conditioner, its parts will eventually wear out, resulting in decreased performance. It'll gradually start taking longer to cool your home or the machine just won't put out enough cold air, but it'll work so hard trying to keep you comfortable that it'll overheat.

Alternatively—and sometimes additionally—the air condition may have internal damage that's impairing its functionality. For instance, power surges can damage the capacitor inside the compressor, resulting in the motor overheating because it's unable to regulate itself properly.

Fixing these problems isn't quite as easy as changing a filter. If your air conditioner is older (between 10 to 15 years), most likely it's just time to replace it. On the other hand, a young unit that's overheating may be damaged, and it's best to call a professional to diagnose and repair the problem.

It's Poorly Located

Overheating problems are typically caused by air conditioners working harder and longer than they need to, and a third reason this can occur is that the units were placed in bad locations. For instance, many A/C units are located in the direct path of the sun, so the machines toil laboriously to cool themselves and the homes.

Another frequent issue is machines that have been installed in rooms that are too big. Many homeowners are surprised to learn air conditioners must be sized for the spaces where they'll be installed. A unit too small for the home will run longer and turn on more often to maintain the desired temperature, which can lead to overheating problems.

Some location issues can be resolved more easily than others. You could relocate the A/C unit to a shadier area or plant trees that help block the sun's rays if direct sunlight is the trouble. On the other hand, undersized air conditioners typically have to be replaced, though installing fans or additional window units may help in the interim.

For help with your overheating air conditioner, contact a local air conditioning repair technician.