Do you want to learn how to install a smart light switch in your home? It's easier than you think.
We'll show you how to replace an old light switch with a new smart switch that can be easily controlled from your phone or tablet.
What You'll Need to Begin
- Smart light switch
- Smartphone or tablet with wireless access
- Slotted screwdriver
- Phillips screwdriver
- Digital multimeter or voltage tester
- Wire nut connectors
Before You Start
In our example, we'll be using a TP-Link Switch that needs a neutral wire for installation. This light switch will not work correctly without this neutral connection. While most modern homes were built with a neutral wire, some older homes were not.
For those homes, we recommend buying a switch that doesn't need a neutral connection.
Disclaimer
To complete this installation, you'll need to access the 120v power supply in your home. It is important to verify all electrical connections are off before disconnecting any wiring. Failure to do so can cause serious injury. If you're not comfortable working with electricity, please consult a professional electrician before beginning this project.
1. Turn off the Power at the Breaker
The first step to installing your new smart switch is to turn the power off at the breaker box. Find the breaker box, and flip the breaker connected to the old light switch. If your breakers are not labeled, then you'll have to try switching different breakers off until you find the right one.
Next, verify there is no power to the light by flipping the old switch. The light should not turn on.
2. Remove the Old Switch
Using the slotted screwdriver, remove the switch cover plate. Then, use a Phillips screwdriver to remove the two screws holding the switch inside the junction box.
Most standard light switches have two black wires attached to the switch, a red traveler wire if it's a three-pole switch, a white or gray neutral wire, and a bare copper wire attached to a green ground screw. Remove all wiring that is attached to the old switch.
In our example, the neutral wire is tucked into the junction box and will need to be pulled forward to connect to our smart switch. The red wire will not be used. We'll cap that with a wire nut and tuck it back into the junction box.
3. Verify Line and Load Wires
Next, you'll need to determine which of the two black wires is your line (the wire that supplies power from the breaker box) and which is your load (the wire that feeds the light after the switch). Turn the breaker back on, and using your multimeter or voltage tester, check for voltage coming from the wires.
Standard household voltage in the United States registers at around 120v. If your multimeter states anything vastly different during this test, then there is a problem and you must consult a licensed electrician before proceeding.
To check for voltage using a multimeter
Set your multimeter to V~ (alternating current). Select 200A. Holding the probes of the multimeter, touch the metal portion of one probe to the bare copper ground wire, and touch the other probe to one of the black wires. If there is voltage at that black wire, you've found your line. No voltage means that wire is the load.
In our example, the multimeter is connected to the line wire because 120.8v is shown on the display.
Note: Once you've turned the breaker back on, the wires inside your junction box are live. Touching live wires can cause serious injury. Never allow yourself, children, or pets to touch bare wires when they are powered on.
After you've verified your line and load wires, you'll need to shut off the power at the breaker box before you continue. Use your multimeter or voltage tester to verify the electricity is off.
Note: Some switches will have a red wire connected to the old switch. This wire is known as the traveler wire, and denotes that the switch is a three-pole. Three-pole means that the light may be controlled by more than one switch. Many times, home manufacturers will use these types of switches in hallways or at the top and bottom of stairs.
If your switch has a red traveler wire attached, you'll need a switch that works with three-pole connections. Smart switches that do not have three-pole connections are not suitable for three-pole use. Consult your smart switch's owner's manual for more details.
4. Connect the New Switch Wiring
Connect the line and load wires to the appropriate terminals on the new switch. Then, connect the neutral wire followed by the bare copper ground wire. If your switch uses wires that are already attached, use wire nuts to splice the connections together. Any unused wires should also be capped with a wire nut before being reinstalled.
Note: Do not use any method besides wire nuts to connect household wiring. Electrical tape and butt connectors are not rated for a project of this nature. If you don't have the proper wire nuts, you'll have to make a trip to the hardware store before you continue.
5. Test the New Switch
Mount the new switch into the junction box using the supplied Phillips head screws. Do not overtighten these screws. Turn the power back on at the breaker, and test the switch by turning on the light. If everything works properly, install the new switch faceplate. Unfortunately, if you didn't connect things correctly, you'll have to turn the breaker back off and figure out where you went wrong.
In most cases, the fix is to switch the load and line wires at the new switch. The other common issue that many people face is an insecure ground wire, or a poor connection at one of the wire nuts.
6. Connect the Switch To Your Wireless Network
Next, you'll need to connect your new smart switch to your home network. This may require installing a specific app on your Android or iOS device. Download the app per the instructions in your switch documentation.
In most cases, this process consists of accessing the switch's network in your smartphone settings, switching back to the manufacturer app, and entering your wireless network credentials. Some devices might also ask you to scan a QR code to populate into apps like Apple Home.
Our switch uses the Kasa Smart app. In Kasa Smart, adding a new device is easy. Open the app and tap the + button in the upper right corner of the screen. Choose Device, then select Smart Switches. Select your smart switch model, and connect to your wireless network.
You'll be asked if you've already wired your switch. Tap Yes, and follow the remaining prompts. Once you're connected, you should be able to use the app to turn your new smart switch on and off.
Download: Kasa Smart iOS | Android (Free)
Enjoy Your New Smart Light Switch
Smart switches offer convenient control of your home's lighting from a tablet or a smartphone. These switches are widely available and can be found online or at many hardware stores. Despite the many different brands available, hardwiring one of these switches should follow this process.
A smart switch is an inexpensive way to upgrade your existing smart home setup. And if you've followed the instructions in this guide, you'll ensure a safe installation that will increase the overall enjoyment of your home.
