The condenser unit of an A/C system has several components that work together to ensure that cool air is produced and pumped into your home. One of the more important components is the capacitor. It is shaped like a cylinder and is responsible for sending a jolt of energy to the motor so the condenser unit can start up. Once the condenser unit is running, the capacitor will continue to provide energy.
When the capacitor stops working properly, your A/C system may start experiencing problems. Luckily, issues caused by a bad capacitor can be repaired by hiring an HVAC contractor to remove the old capacitor and install a new one. Some common signs that you have a bad A/C capacitor include:
Lack of Cool Air Blowing Through the Vents
When your air conditioning unit turns on, the condenser unit produces cool air and the blower fan pushes it through the vents and into your home. When a capacitor is bad, it is not able to provide enough energy to get the motor of the condenser unit to start up, so cool air can't be produced. However, the blower fan will still be running. If it sounds like your air conditioner is running inside your house but the air coming out of the vents is warm instead of cool, there is a good chance that your capacitor needs to be replaced.
A/C Turns Off for Unexplained Reasons
In some cases, a capacitor may have just enough of a charge to get the motor of the condenser unit running, but it can't provide enough energy to help power the motor for an entire cycle. If the capacitor is very weak and has very little charge, your air conditioner may just turn off shortly after turning on, even if your home has not yet reached the temperature set on the thermostat.
Humming Sound from Condenser Unit
If you notice any issues with your home's air conditioning system, take the time to go outside and inspect the outdoor condenser unit. Make sure that you examine the unit after you have turned your A/C on. If your capacitor is bad, you will likely notice that the condenser unit is making a humming sound, and the fan is not rotating at all. In this type of situation, it is best to contact an AC repair contractor as soon as possible so the capacitor can be checked and replaced, if needed.