Symptoms
- Smart switch won't power on after installation
- Only two wires (plus ground) found in the switch box
- Switch flickers the light even when off
Likely causes
- CommonHome wired without a neutral wire at that switch locationMany homes built before the 2010s only ran hot and traveler wires to switch boxes, not a neutral.
- PossibleNeutral wire present but bundled and not identifiedSometimes a neutral exists in the box but is capped off and unused.
- PossibleWrong smart switch model purchased for the home's wiringNot all smart switches are designed to work without a neutral.
What to do
- Turn off power to the switch at the breaker and verify with a non-contact voltage tester.
- Open the switch box and count the wires present, looking for a white neutral wire, often capped separately if unused.
- Check your smart switch's installation guide to see if it requires a neutral or has a no-neutral compatible mode.
- If no neutral is available, consider a smart switch model specifically designed to work without one.
- If you're not confident identifying wires safely, stop and have an electrician confirm what's available.
- Reinstall the original switch if you can't safely proceed, to keep the circuit working while you sort out options.
Tools and parts
- Non-contact voltage tester
- Screwdriver
No-neutral smart switchSearch: “smart switch no neutral wire required”
When to call a pro
Call a licensed electrician if there's no neutral wire and you want a hardwired smart switch that requires one, since adding a neutral often means running new wire.
Safety
Use caution
Always shut off power at the breaker and verify with a voltage tester before opening a switch box.