How to Know if the Capacitor in Your Furnace Is Damaged
Fighting Over the Thermostat? Consider Zone Control Cooling

December 19, 2014


A lot of articles you’ll find on the topic of home heating talk about the actual heating parts of a furnace. The pilot light, the burners, the heat exchanger, etc. all get a pretty good amount of attention from both experts and homeowners. What isn’t often discussed, however, is that your furnace relies on electricity whether it is combustion-based or not. Without an electrical current, your furnace’s air handler would be unable to circulate air through your house and the whole machine would be pointless. With that in mind, let’s take a look at how one of the most important electrical parts in your furnace works. Then, we’ll discuss how you can identify issues with it.

The Capacitor

Every furnace contains an air handler, comprised of the fan, motor, and other parts necessary to circulate air through the ducts in a home. When the thermostat tells the furnace to start, the air handler starts at more or less the same time to actually distribute the heat the furnace produces. As the electric current runs into the air handler, the capacitor is the part responsible for actually closing the circuit and allowing the thing to start. Without the capacitor, therefore, the air handler would be unable to start.

Detecting Problems with the Capacitor

The easiest way to identify a problem with your furnace’s capacitor is to see if the fan starts blowing when you turn on the heat. If the capacitor is malfunctioning, the furnace will still turn on but the fan will not. There are variations on this issue, of course. If the fan seems to be turning on and off randomly at different times while the furnace is running, it’s a good sign that the capacitor is malfunctioning. Clicking sounds coming from the furnace are also a common sign of a failing capacitor, as well as a burning smell.

If you think you may have a problem with your capacitor, or with any other part of your furnace, call Bronco Plumbing Heating and Air. We provide furnace repairs throughout the Sacramento area.