An HVAC capacitor is a component that’s no larger than a beverage can, yet when it goes bad, the effects are immediately noticeable. The air conditioning contractors at J&M share a look at how you can identify a bad HVAC capacitor.
An HVAC capacitor is a cylindrical component that looks like an aluminum beverage can without a label. It stores energy in an electrostatic field, which helps stabilize the voltage that runs through the HVAC system. Each of the main HVAC motors (blower, compressor and outdoor fan) have their own pair of capacitors: one capacitor helps start the motor,while the other helps keep it running.
Signs of a Bad HVAC Capacitor
It’s important to note that, unlike air filters or thermostat batteries, HVAC capacitors aren’t intended to be user-replaceable. If you notice one or more of the following signs, you need to contact your air conditioning technician.
Low Output — If your air conditioner isn’t blowing cold air (or isn’t blowing air at all) even after you’ve performed the right troubleshooting steps, this could indicate a bad HVAC capacitor. Low output also indicates inefficiency, which means you’ll be spending more on energy costs without fully cooling your home. The constant strain on your HVAC system could also result in premature damage.
Humming Noises — New HVAC systems have a characteristic noise upon being turned on, and when the thermostat ramps up its output. If the HVAC system emits a continuous humming noise, this indicates an HVAC capacitor that’s about to fail.
The HVAC System Intermittently Turns Off — Bad HVAC capacitors cause intermittent shutdowns,, and can also cause the HVAC system to “hesitate” upon starting up. Some homeowners assume the worst and call for HVAC replacement prematurely. If this happens to you, check for other signs, and call for repairs.
The HVAC System Is Beyond Its Expected Lifespan — HVAC systems typically last for ten to 15 years with proper care and maintenance. If yours is nearing this age and has never had its capacitors replaced, chances are it will need a new one soon.