How to Correctly and Easily Install a Dimmer Switch

If your dimmer switch creates a buzzing noise, try lower-wattage bulbs.

Dimmer lights provide a relaxing environment in the evening and less severe illumination in the early morning. From kitchen islands to bathrooms, replacing standard light switches with dimmer switches allows for softer lighting almost anywhere in the home. The devices work with incandescent bulbs and certain compact fluorescent bulbs manufactured for use with dimmers. Whether you select a toggle or another style of controller, choose a dimmer switch that can handle the light's load. For example, if the total wattage of the bulbs adds up to 600, install a dimmer that's rated to operate at 600 watts or more.

Things You'll Need

• Voltage tester
• One-way dimmer switch
• Screwdriver
• Wire nuts
• Wire cutter
• Wire stripper

Instructions

1. Shut off the power to the circuit at the circuit breaker. Flip the switch to ensure that the power is cut off to the light.

2. Remove the existing switch plate. Remove the two screws that hold the switch in place and gently pull the switch out. Don't touch any wires until you've used a voltage tester to double-check that the power is off. Once you've confirmed that the wires aren't carrying a current, disconnect all wires from the back of the existing switch.

3. Connect the end of the bare or green ground wire in the electrical box to the green grounding screw on the dimmer. If the switch has a green wire instead of a green screw, twist the tip of the green wire from the dimmer around the ends of the green or bare copper wiring in the electrical box; use a wire nut to cap the ends.

4. Examine the dimmer switch. If your model comes with black pigtails, or short wires protruding from the dimmer, secure each pigtail to a black wire in the electrical box with wire nuts. Leave the white wires capped together in the back of the box. If your dimmer has two screw terminals on the side and no wires whatsoever, connect each black wire in the box to a terminal. Tighten the terminals with a screwdriver.

5. Gently push the wires back into the electrical box along with the switch. Drive in the two mounting screws that hold the switch to the box. Reinstall the switch plate. Turn the power back on at the circuit breaker.

Tips & Warnings

• If the tips of the black wires in the electrical box are too worn to make a good connection, snip off the ragged ends with a wire cutter and remove 1/2 inch of the black coating with a wire stripper to reveal new wire.

• Higher-quality dimmers are less likely to produce a buzzing noise than lower-grade dimmer switches. Buzzing sounds also occur when dimmer switches cannot handle the light's electric load.

References

• Danny Lipford: How to Install a Chandelier and Dimmer Switch
• Ron Hazelton: How to Install a Dimmer Switch
• Ask the Builder; Dimmer Switch; Tim Carter
• Home Depot: Installing a Dimmer Switch