At first sight
Easy physical installation Attractive appearance Screwless cover plate included Very easy wireless setup
The test unit had a problem with its air gap. May never support Expensive Matter
Wemo’s new dimmer supports HomeKit and Threads, and installs easily, but it’s going to cost you (and it’s not Matter-certified).
Price at time of review
Today’s best prices: Wemo Smart Dimmer with Thread (Model WDS070)
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Apple-centric homeowners have more choices than ever when it comes to outfitting a smart home, and the Wemo Smart Dimmer with Thread is a solid, if expensive, choice for the HomeKit and Thread crowd.
There’s not much to the Wemo Smart Dimmer, which only supports single-pole installations and offers a fairly straightforward collection of standard dimming features. Upside, it will work with or without a neutral wire in the electrical box (Belkin recommends connecting a neutral wire if one is available).
You’ll tap the rectangular switch to turn the connected load on and off, press and hold the top and bottom dimples to brighten and dim the light respectively, and double-tap them to bring things to maximum or minimum brightness. These maximum and minimum levels aren’t set via an app-based calibration, which is the norm on non-HomeKit devices, but rather via hardware, holding down multiple buttons simultaneously to teach the dimmer your preferred levels.
This review is part of TechHive’s in-depth coverage of the best dimmers and smart switches.
I found installing the Wemo dimmer to be easier than most switches I’ve worked with. The device has dual wiring holes on the back for each of the four required connections, including ground. This makes wiring quite simple: just push in the wire(s) and tighten one screw; the only wire connection i had to make was to my house neutral line. A single white pigtail and nut are included in the box for this purpose, though the included nut wasn’t big enough for wiring inside the wall in my house, so I had to get my own. The size of the switch is a reasonable size and I found that fixing everything flush and cleanly to the wall was easier than many competing units.
Once connected, setup is done entirely via HomeKit, Bluetooth, and Threads. If you’re lucky, you should be able to connect just by holding your phone close to the center of the dimmer (via near-field communication or NFC). I ended up having to type in the 8 digit code printed on a sticker on the switch (under the cover plate); once i did that everything went quickly. HomeKit pros know that the iOS Home app is pretty straightforward (you can’t use the Wemo app to control your device), providing a simple manual dimming slider and a handy scheduling system; plus, the ability to connect the dimmer to the wider HomeKit ecosystem. All of the above worked fine in my tests, and my test light now dutifully turns itself on at dusk every night without complaint.
I encountered a hiccup with the dimmer air gap switch, a manual safety cutout recessed under the headstock. While this switch should be flush with the switch plate, mine sticks out about a millimeter and is very loose. The switch still works as it should, but if you flick it, it’s easy to trip, causing the dimmer to lose power entirely. There seems to be something wrong with the air gap spring loading mechanism on this particular unit; Belkin says this is a random issue and at press time they were sending a replacement.
One point of note is that the dimmer does not and probably will not support Matter. A Belkin representative wrote in response to a question about the matter: “The Wemo Smart Dimmer works exclusively with HomeKit on Thread for a more responsive, reliable and secure smart home experience without the hassle of third-party apps. We remain adamant that Matter will have a significantly positive impact on the smart home industry, but we have made the decision to take a big step back, retool and rethink our approach to the smart home space. We are currently pausing development of our Matter products, but when we will be able to bring differentiated products to market, we will.”
At $60, the dimmer isn’t cheap, though its Thread and HomeKit support, sleek design, and easy installation give it an edge over some of the other options in this category. If you’re on the HomeKit bandwagon or bust, it’s worth considering.