What You'll Need

Step-by-Step Setup

Identify main switch location: The Wemo 3-way replaces ONE switch—the one with the line (power from panel). The other switch stays as a standard 3-way switch.
Turn off power: Switch off the circuit breaker. Verify with voltage tester at both switch locations.
Identify wires at main switch: Find line (hot), load, travelers (2 wires going to other switch), neutral, and ground.
Remove existing switch: Unscrew and disconnect, noting which wire is connected to which terminal.
Connect the Wemo 3-Way:
- Black wire → Line (hot)
- Red wire → Load (or first traveler)
- Green wire → Ground
- White wire → Neutral bundle
- Blue wire → Remaining traveler
Keep secondary switch standard: The other 3-way switch remains unchanged but will work with the Wemo.
Mount and restore power: Install the switch, attach faceplate, and turn on the breaker.
Download Wemo app: Add the switch and connect to Wi-Fi.
Test both locations: Verify the light can be controlled from both switches and the app.

Other switch doesn't work: Check traveler wire connections at both switches. The blue wire must connect to the correct traveler.
Light stays on/off regardless: Verify line and load wires aren't swapped. Check that travelers are correctly identified.
Wemo controls light but manual switches don't: Traveler wires are likely connected incorrectly. Swap blue and red wire connections.
App shows wrong state: 3-way setups can sometimes show incorrect status. Refresh the app. The switch will still function correctly.
Setup fails: Factory reset by pressing the switch button for 15 seconds. Restart the setup process in the app.