An air conditioning system is quite complex and requires a number of components to work properly in order to function. One of the components that help the air conditioner operate and create cold air is called a capacitor. A capacitor is a cylindrical-shaped part that stores energy; it helps provide the power needed to get the air conditioner to start running and continues to provide power while the air conditioner is running. While capacitors are designed to be durable and long-lasting, they rarely outlast the lifespan of an air conditioning unit and need to be replaced. Some common signs that your air conditioner's capacitor is failing include the following.

Humming Sound from Outdoor Condenser Unit

If you are a homeowner, it is a good idea to inspect your air conditioner's outdoor condenser unit on a regular basis. Ideally, you should do your inspection right after you set the thermostat to turn your air conditioner on. A condenser unit will always make noise when it starts up, but pay attention to see if you notice a humming sound beforehand. If you hear humming before the condenser unit is up and running, it is a red flag that your capacitor is no longer functioning properly and needs to be replaced.

Your Air Conditioner Runs Erratically

When all of the components in your air conditioner, including the capacitor, are in good working order, your air conditioner will run until the inside of your home reaches the temperature set on your thermostat and will then turn off. Since the capacitor provides a source of power to get the air conditioner running and keep it running, you will notice changes when a capacitor is about to fail. When a capacitor is bad, your air conditioner may turn off suddenly, power on unexpectedly, or cycle on and off frequently. If you notice that your air conditioner is running erratically, it is a good idea to contact an HVAC company and have the capacitor checked.

Unusually High Electric Bills

If you live in a warm or hot climate where you use your air conditioner often during the summer months, your electric bill is most likely higher during these times. However, if you see a big spike in your bill, a failing capacitor could be the cause. When a capacitor is failing, the entire condenser unit has to work harder to stay running. This means that your condenser unit may be using more electricity, resulting in a larger electric bill. 

Reach out to a professional who works on air conditioning units to learn more.