LED lighting for the home has come a long way in recent years and is now available in everything from standard-shaped screw-in bulbs to futuristic flexible lighting tapes. And yes, LED lights can work with dimmers, but not all bulbs and fixtures work equally well—or even safely—with all dimmers. The bottom line is compatibility. Some LED bulbs are designed for use with standard dimmer switches, while some fixtures, such as undercabinet and recessed lights, may need special LED dimmers for proper performance.
Conventional incandescent light bulbs are compatible with most types of dimmers and can be adjusted to almost zero light output. By contrast, many LED bulbs won't work with standard dimmers—the kind you most likely have in your house. Also, even dimmer-compatible LED lighting typically can't be dimmed as low as incandescent and may turn off completely before the dimmer is at its lowest setting. Another difference is in the color temperature, or the perceived warmth of the light. Incandescent bulbs tend to emit a warmer, softer glow the more they are dimmed. With LEDs the color temperature doesn't change with dimming, so you usually don't get the familiar soft ambience as with incandescents. However, some LED products simulate this effect by combining diodes (the tiny light-emitting sources of LEDs) of different color temperatures in the same bulb.
The easiest way to put an LED light bulb on a dimmer circuit is to use a bulb that's compatible with standard (incandescent) dimmers. Start with one bulb and see how well it works on your dimmer; you may decide to upgrade the dimmer switch and/or the bulb. Another option is to replace your old dimmer switch with an LED-compatible dimmer. This still requires a dimmable LED bulb but is likely to provide better dimming performance than a dimmable bulb on a standard switch. If you have LED undercabinet or recessed fixtures, you may need an electronic low-voltage dimmer (ELV) or a magnetic low-voltage dimmer (MLV). Check the light bulb or fixture packaging or contact the fixture manufacturer or retailer for recommendations. Many manufacturers and retailers have online compatibility charts to help consumers match specific switches and bulbs or fixtures.
Making the Switch
If you swap out an old incandescent or CFL bulb with a new dimmer-compatible LED but you're not happy with the performance, your best bet is to replace the old dimmer switch with an LED dimmer that's compatible with the new bulb. This allows you to keep the new bulb while upgrading to a switch that likely will work better with other LEDs down the road. A proper match between the dimmer and bulb will not only improve dimming performance, it's also likely to increase the life of the bulb and may save energy in the long run, especially if you use really low levels of light at times (levels that might not be achievable with a standard dimmer).