Why will my LED bulbs not dim properly?

LED bulbs and old dimmer switches often do not work well together. Old dimmers were designed for incandescent bulbs which use much more power. LED bulbs use very little power, and this can cause them to flicker, buzz, not dim below a certain level, or switch off suddenly at low settings. The fix is usually to replace the dimmer switch with an LED-compatible version — look for one labelled 'trailing edge' or 'LED compatible'. You also need to make sure the LED bulbs themselves are dimmable — not all LEDs are. Check the bulb packaging. Both the switch and the bulb need to be compatible. A qualified electrician can replace the dimmer switch.