Leviton Decora Smart WiFi Motion sensing Dimmer D2MSD-1BW review

Light switches may not be the first thing you would think of when it comes to making your home smarter, but they are one of the simplest and most important ways to take control of your home. Once you get control of your lighting, the rest becomes much easier. And they are pretty easy to install these days: devices like the 2nd generation Leviton Decora Smart WiFi Motion Sensing Dimmer that I tested here are just drop-in replacements for your old light switches that open up a range of possibilities. 

Want to set one dimmer to control several separate lights? Want to set a light to glow dimmer at night, so you aren’t blinded when you get up to go to the bathroom? This one can do that and much more. Its breadth of features makes it one of the best smart light switches around, but you’ll want to read the rest of our Leviton Decora Smart WiFi Motion Sensing Dimmer review first.

Leviton Decora Smart Motion Sensing Dimmer review: Design

The D2MSD has a clean, simple design with a big button to press to turn the light on manually. On the right of this are two small dimmer buttons and a set of four green LEDs on the other side of the switch light up to show you the dimmer level. The dimmer range can be configured in the app: a useful feature if you want to dim it a little but not close to off. 

Above the main switch is the motion sensor behind a frosted plastic panel. This is a passive infrared (PIR) type, which is triggered by things warmer than their surroundings, like a human body or an animal. A red LED next to the sensor shows when it has been triggered, but this light can be disabled if you don’t want people to realize it. A small multicolor LED below the sensor shows the status of the smart switch, blinking green when it is ready to be set up or red if there is a problem.

Next to the PIR sensor is a small plastic tag. Leviton calls this the Air Gap: pull this out, and the switch and the light socket it controls are completely cut off from the power: a nice feature if you are concerned about getting shocked while changing a bulb.

Overall, the look is less fussy, though perhaps not as futuristic, as the GE Cync Smart Switch Motion Sensing Dimmer.

Leviton Decora Smart Motion Sensing Dimmer review: Installation

The Leviton Decora Smart requires a neutral wire, which allows the switch to power itself even when the light is off. That means it won’t work on old-school light switches where the switch simply breaks the circuit on the live wire without some rewiring. You can usually tell if the switch you are replacing has a neutral connection by unscrewing the cover, pulling the switch mechanism out, and looking at the wires behind it. If you see two or more wire nuts behind the switch mechanism joining white and green wires, you should be good to go. If you don’t have a neutral wire, you can install a dimmer like the Leviton Decora Smart Dimmer DN6HD-1BW, but not a motion sensor. Leviton also has a video that shows the different types of wiring. If you are not certain, consult an electrician. 

Installing the Decora Smart switch involves turning off the power, removing the old switch, then connecting the load, neutral, and ground wires to the appropriately colored cables on the back of the switch: green for ground, black for the line, white for neutral and red to the load line that leads to the light. A yellow line that can be used for a two-pole setup (where more than one switch controls a light) is included, but this usually won’t be required. The included guide describes the process pretty clearly.

The only issue I found during installation is that the switch is large and takes up a lot of space in the switch box. That means you must be careful where you tuck the cables and wire nuts, as they could get trapped or push the switch out at an odd angle if they get stuck behind it. 

Once the switch is wired up, you turn the power back on and wait for the status LED on the front of the switch to blink, which shows the switch is in setup mode. You then use the My Leviton app (available for iOS and Android) to connect the light to your WiFi network and configure it. Again, this process is pretty simple, and I had no issues connecting to a couple of networks. It does support the 2.4GHz frequency band only, though, so it won’t work with 5GHz only routers. 

Once the light is configured, you can give it a name, set the type of LED and connect it to your smart home network. This light supports the big three: Amazon Alexa, Google Home and Apple HomeKit, so it should work with pretty much any device or smart home controller. 

Leviton Decora Smart Motion Sensing Dimmer review: In use

The Decora Smart can handle a wide range of light sources, including LEDs, CFLs incandescent, and the less common Magnetic Low Voltage (MLV) type. It can also dim LED and CFL lights, as long as they are dimmable types. You shouldn’t try and dim a non-dimmable bulb: at best, you’ll get a headache from the flickering, and at worst, you can damage the light. It can handle up to 450W of load for incandescent and MLV lighting or 300W for CFL and LED lights. That’s enough for most home setups. 

I found the motion sensor pretty sensitive: I could trigger it by walking up to about 15 feet away. That’s plenty sensitive for most uses, and the light offers two modes: Occupancy and Vacancy. The first turns the lights on when it detects someone approaching, then turns them off after a preset time of no detected motion. Vacancy only does the second part: you turn the light on manually, then it turns off when it doesn’t detect you in the room anymore. That’s great if you are someone who often accidentally leaves the light on. It’s part of a California standard to save energy by turning off lights in unoccupied rooms (CA 2019 Title 24, Part 6: Vacancy Control Device Requirements for fans of state building codes). 

The My Leviton app is also pretty simple to use, allowing you to control the light, see the status of the motion sensor and configure the settings for the motion detection. This includes things like how long the light stays on after motion is detected, as well as setting the dimming range. The app also integrates the switch with your smart home system. It supports Amazon Alexa, Google Home, and Apple HomeKit. It is unusual for a switch to be controllable through all three major smart home systems, so that’s a big plus if you use more than one or want the option to change in the future without having to swap out hardware.

Leviton Decora Smart Motion Sensing Dimmer review: Verdict

The Leviton Decora Smart Motion Sensing Dimmer combines a lot of different features into a single device: a dimmer, motion sensor, and a smart light switch. It does all this without much fuss, integrating with your existing wiring and Wi-Fi without requiring too much rewiring or the addition of a hub or other controller. That makes it a great pick for a smart home upgrade, and the support for all three of the main smart home standards is the cherry on the cake, as it means that you won’t need to tear them out and start again if you switch from Android to iPhone or Alexa to HomeKit. Among the best smart light switches, this one has it all.