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How to Install a Dimmer Light Switch

Follow these simple tips to save energy and set the mood

Dim is in! If you’ve ever taken a selfie in harsh light, you know what we’re talking about. A simple dimmer light switch is a quick and inexpensive way to transform your room, while shaving your electric bill. What are you waiting for?

Before You Start

1. Look up. If your light is fluorescent or housed in a ceiling fan, a dimmer switch won’t work. In the clear? Determine which wall switch flicks on the light. If more than one switch turns on your fixture, a standard, “single-pole” dimmer switch won’t work. Consult an electrician.

2. Round up supplies. Aside from your shiny, new single-pole dimmer light switch, you’ll need a voltage tester, flat-head and Phillips-head screwdrivers, pliers, a wire cutter and wire connector nuts.

3. Carefully read the manufacturer’s instructions included with your dimmer switch. Any doubts? Call in a pro.

Out with the Old

1. Turn off the power to the light switch at the breaker. Double-check that the electric current isn’t flowing by flicking the switch on and off. (You’ll need a bulb in place to check.)

2. Unscrew the existing switch plate and the screws holding the switch to the wall box. Pull the switch away from the wall to expose the wiring. Now’s a good time to triple-check that the power’s off. Test each wire in the circuit with the voltage tester.

3. Disconnect the wires from the old light switch. Then, examine your existing house wires. If they’re too bent to work with, use the wire cutter to snip the ends clean, trimming the rubbery insulation from the ends as needed. Don’t cut too much wire—short wires are tough to manipulate.

In with the New

1. Locate the house’s ground wire; it should be green or bare copper. Connect that wire to the dimmer’s ground wire. Twist their ends together, top the twist with a wire connector nut, then twist to tighten again.

2. Connect the remaining dimmer light switch wires (they’re probably black) to the remaining house wires (those may be any color) using the same twist-and-nut method. Be sure that no bare wire is exposed beneath the nuts.

Final Touches

1. Guide the dimmer light switch onto the electrical box, tucking the wires behind it. Screw the dimmer switch to the box (you want a tight, flush fit).

2. Attach the wall plate and tighten the screws to the wall. If your dimmer has a no-screw design, attach the wall adapter to the dimmer and click the wall plate into place.

3. Head back to the breaker and turn on the power. Return to the dimmer and switch it on to test. Now lower those lights!