Home / Style Guide / Learn About LED / LED Troubleshooting LED Troubleshooting Flickering, humming or buzzing With incandescent bulbs, dimming is simple, since the brightness of the bulb is directly related to the voltage applied. Adjust the voltage applied by raising or lowering the dimmer and the brightness of the bulb will change accordingly. The same isn't always true with LEDs. If you use an LED bulb or fixture with an incandescent dimmer switch, you may find that the bulb: Doesn't turn on at all. Only works at 100 percent brightness. Turns on but hums or buzzes loudly. Flickers at specific or all dimmer levels. If using a dimmer switch, make sure your LED fixture or bulb is labeled as “dimmable” before installing. If it’s still humming or buzzing, check that you’re using the right dimmer switch for the LED. Choosing a dimmer LEDs feature a complex circuitry inside, referred to as the driver. This driver determines how the LED will react to different types of dimmers -- and there are A LOT of different types: incandescent phase control, leading-edge, trailing-edge, three-wire Lutron, or 0 to 10V dimmers. An LED might dim just fine with one type of dimmer, but that doesn't ensure it will work with others. Integrated LED fixtures should indicate which type of dimmer is required; LED bulb packaging should do the same. NOTE: Not all LEDs are dimmable The manufacturer decides whether to add a dimming capability to the circuitry of an LED bulb or fixture. Often, this means cost savings for consumers who don't need dimming capabilities. See Kichler dimmable products. 5 Tips for LED & Dimming Be sure to choose an LED bulb that the packaging describes as “dimmable”. Choose bulbs or integrated fixtures from established lighting manufacturers. Aside from dimming considerations, established brands are also more likely to offer better product warranties, longer lamp life and more customer support. Read the label and select the dimmable LEDs with the highest maximum lumen output specified for the fixture, for a greater dimming range. Check manufacturer websites for dimmer compatibility recommendations. Don’t use a standard dimmer – choose a dimmer specific for LED.