Air conditioners have a lifespan of up to 20 years, but that doesn't mean they'll operate trouble-free the entire time. There are a number of reasons your air conditioner may break down and stop cooling your home, and a failing capacitor is commonly the cause. Here's more information about how to diagnose this problem and what you can do about it.
What Air Conditioner Capacitors Do
Air conditioners contain several different motors that help it do its job. These motors require a jolt of electricity every now and again to either start or continue functioning. A capacitor's job is to retain an electrical charge and provide it to the associated motor when it's needed. If a capacitor loses its ability to get or stay charged, the motor it's attached to may not work properly, and you'll feel the difference in your home.
Depending on the type of air conditioner you have, your unit may have up to four capacitors powering different parts of the machine:
- Outside fan motor capacitor powers the fan on the air conditioner that pulls air through the exterior coils.
- Start capacitor is an extra device on some models that provides additional charge to other motors in the appliance.
- Indoor fan motor capacitor powers the blower designated to send air into the home.
- Compressor capacitor sends energy to the compressor, which is responsible for cooling air. Many compressors actually have dual capacitors, because this part is the one that fails most often.
A/C capacitors go bad for a number of reasons. Many times it's simple wear and tear. Remember, air conditioners can last for two decades or more and are constantly used for months on end to keep living areas cool. Even the most high-quality part will break down under this type of demand.
Environmental elements are also responsible for causing capacitors to fail. In most cases, a capacitor may short out because it got too hot, which may be the result of where the appliance is positioned. If it's sitting in the direct path of the sun, you can be sure the parts on the unit will wear out faster because of excess heat. However, dust, debris, electrical surges, water, and rust have also contributed to capacitor failure.
Fixing a Broken Capacitor
The good news is broken capacitors are an easy fix. The challenge is in diagnosing which one is causing the problem. If the outside fan is not turning, take a stick and push the blades. If the fan starts moving when you do that, the capacitor attached to it isn't working or is in the process of failing.
If the outside fan is working and the compressor is humming but there is no cold air blowing through the vents in your home, then the interior fan motor may not be turning. Likewise, if there is air blowing through the home and the outside fan is turning but the compressor is silent, then the compressor is likely the source of the problem. And if nothing is working at all, then the start capacitor may be the source of the trouble.
However, it's best to confirm your suspicions by testing the capacitors using a multimeter. You'll need to consult your owner's manual for the location of the different capacitors in your machine. If you lost your manual or it doesn't have that information, you can usually find out what you need to know by conducting research online. Be sure to cut off all power to the air conditioner first before you start the testing process; otherwise, you could electrocute yourself.
If the multimeter doesn't produce a reading, the capacitor is bad, but you can easily purchase the part from a local home improvement store and replace it.
For more information on diagnosing capacitor problems or help fixing your air conditioner, contact an air conditioning repair specialist.