What is a Neutral Wire and What to Do If You Don’t Have One

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Neutral wires are necessary for many smart switches to work. Here’s what you need to know.

Three in four Americans bought a smart home techdevice in 2022, and that number has only gone up since then. We’re not sure how many of those people went to install a new smart switch and realized that electrical wiring can be confusing, but we bet it was a lot.

If you’re among those numbers, don’t worry. We’ve got all the information you need about neutral wires to get you on your way to smart home glory.

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What is a Neutral Wire?

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1. What are neutral wires

Behind your light switches is a nest of wires that work hard every time you turn on the light.

Neutral wires deliver a small amount of power to smart switches. When you turn off a normal switch, the circuit breaks. However, with a neutral wire connected, that trickle of power stays on so your smart light switch can stay connected to your home Wi-Fi.

Neutral wires are mainly found in newer homes (built after 1985) and are required by most modern US electrical codes.

Don’t get shocked!

To avoid an electric shock, always turn off the voltage to a switch or outlet at the circuit breaker before removing the cover.

2. Different kinds of wires

Crack open a light switch box and you’ll see a bunch of different wires. How do you know which is which?

Image showing black wires in an open outlet

Katie McEntire, SafeWise

Typically, when you look behind a switch plate, you’ll find load wires, hot wires, ground wires, and neutral wires. You can usually tell which is which by the color of each wire. According to the United States’ National Electric Code, or NEC, the black wires are the hot wires (live wires) and load wires that carry electrical current to your light switch. The green wire (if there is one) is the ground wire

Open outlet with a white wire and two black wires.

Image: Katie McEntire, SafeWise

As for that white wire? That’s a neutral wire. Unless you already have a smart switch connected, the chances are that they’ll be hanging out with a wire nut on and waiting for you to connect them.

Sometimes, the wires won’t be the color they’re supposed to be. One foolproof way to find the neutral wire is to look at the printing on the wire. Often the neutral wire will be printed with an “N” or “Neutral.”

3. Do you need a neutral wire for a smart switch?

So, now that we’ve covered what these mysterious wires are and what they do, one question remains: What do you do if you don’t have neural wires for a smart switch?

Thankfully, you don’t need one. Not all smart switches need neutral wiring. Some of our favorite brands that don’t need neutral wires are Lutron Caseta and GE CYNC.

Just be aware that many of the switches that don’t need neutral wires will need a smart hub to work. It’s a small trade-off. You can easily find out if a hub is needed in the fine print and product description before you spring for a new light switch.

Alternatively, to avoid the whole “hub situation,” you’ll need to have an electrician install a neutral wire. While it’s a simple process, it will require ripping out part of the wall around the outlet to install new electrical wires, which is something you probably want to avoid unless you’re renovating.

Final word

In the end, all you need to know is that the white wires behind switch covers are neutral wires. Though they aren’t essential to installing a smart switch, they let you skip setting up a smart hub for the switch to work.

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