How to Replace a Three Way Switch

mediumHome Repair30-60 minutes10 steps

Safety Warnings

Turn off the power at the main circuit breaker before starting work to avoid electrical shock.
Use a voltage tester to verify the power is off before touching any wires.
If you are unsure of the wiring configuration, contact a licensed electrician.

Voltage Tester — check locally

Screwdriver — check locally

Wire Stripper — check locally

Needle-nose Pliers — check locally

Three Way Switch — check locally(1)

Wire Nuts — check locally(as needed)

Electrical Tape — check locally(1 roll)

Turn off the electrical power at the circuit breaker panel.

Remove the wall plate and the screws holding the old switch in the electrical box.

Tip: Keep screws in a safe place to avoid losing them.

Pull the switch out of the box and use a voltage tester to confirm no wires are live.

Identify and label the common terminal wire (usually black or darker) and the two traveler wires before disconnecting.

Disconnect the wires from the old three way switch.

Connect the common wire to the common terminal (usually a darker colored screw) on the new switch.

Connect the two traveler wires to the two remaining traveler terminals.

Connect the ground wire to the green grounding screw on the switch.

Carefully tuck the wires back into the electrical box and screw the switch into place.

Replace the wall plate, restore power at the breaker, and test the switch functionality from both locations.

Labeling wires before disassembly is critical for three way switches because the order of travelers can vary.

Synthesized from 5 verified sources:

Gutenberg: Electrical GuideView →

Gutenberg: Dwelling ConstructionView →

Gutenberg: Simple Plumbing Repairs (FB 1460)View →

Gutenberg: Electricity for the 4-H ScientistView →

USDA Farmers' Bulletin (Gutenberg)View →