A Beginner's Guide to Smart Switches

We’ve installed our thermostats, set up our doorbell and are loving the control it gives us. We’re starting to see the possibilities that home automation brings. Some of the key components that any smart house needs live on the walls of just about every room in our house. That’s right, we’re going to talk about light switches.

We physically interact with light switches every day. They are some of the most simple and reliable pieces of equipment in our houses. Every family member and guest understands how to use them without instructions. And therein lies the problem. How do we change out a simple, reliable, and intuitive piece of hardware for an inherently more complex one without sacrificing reliability and intuitiveness? Each manufacturer tries to answer these questions in its own way; some more successfully than others. Let’s examine some of the factors that go into choosing a good switch.

  • Installation: How easy is it to install? Will it work your bulbs? Does it need a neutral? And oh yeah, what’s a neutral?
  • Quality: How reliable is the switch? Does it work smoothly and quickly?
  • Aesthetic: Does it look and work like a normal switch? Does it match my existing switches?
  • Features: What can I do with it beyond turning my lights on and off?

Installation. Old fashioned switches are very simple devices. Electricity runs from your service panel, through the switch, up into the light and back to the service panel in a loop. This continuous flow of electricity provides power which causes the light to glow. When the switch is flipped off, it breaks the circuit which interrupts the flow of electricity causing the light to no longer have power.

Adding a smart switch makes this more complicated. Because the switch has a bunch smart “stuff” inside; things like computer chips, Z-Wave radios, and LEDs, it needs a constant source of power to operate. In the diagram above, we see that a switch breaks the circuit it's attached to when it's open (or off) which means electricity cannot flow through the circuit at all, even to power the switch itself. Fortunately, most newer homes have an extra wire in the switch housing (also called the box)  that connects back to the breaker box called the “neutral” wire. This wire allows a complete circuit between the switch and the power source that is always on, even when you turn the switch off. As you can see, installing a smart switch usually requires you to have a neutral in your box.

However, older houses built before neutrals become required by code quite often do not have neutrals in the switch box. For these cases you’ll either need to have an electrician run a neutral for you (probably expensive!) or use a smart switch that doesn’t require a neutral. “Hey!” you might be thinking. “How will the switch power itself without a neutral?” Some switches are designed to let a small amount of power leak through the entire circuit, even when the switch is off. It uses that trickle of electricity to power itself. However, in lights that need very little electricity, like single LED bulbs, the small amount of power allowed through can cause the LED bulbs to flicker when the light is supposed to be off. Lutron, the pioneer of this type of switch, states that their no-neutral Caseta switches  have a minimum load of 25W to avoid flickering. While 25 watts doesn’t sound like a lot, a typical LED bulb that is equivalent to a 60W incandescent bulb uses only 13 - 15 watts! So if you have a single 60W equivalent LED bulb, it will most likely flicker when used with a no-neutral switch.

The next consideration when it comes to installation is how many switches control the same set of lights. If you have 2 switches controlling the same light fixture, you have a 3-way switch. If you can control it from 3 switches, it’s called a 4-way switch. You’ll need to make sure the smart switch you buy is compatible with your particular setup. The GE Enbrighten switch  will work in a  3-way setup but requires you to replace the second switch with one of their “add-on” switches to work properly.  The Zooz Zen 26/27  is amazing in these scenarios because not only do they work with whatever second switch you already have installed, you don’t have to change the way that second switch is wired! You just replace the main switch (the one that has the line coming from the breaker panel) and it just works. Inovelli, one of my favorite companies, is releasing a switch that has the same great 3-way easy setup as the Zooz but also can be used without a neutral (albeit with the same 25W minimum as the Caseta). The Lutron Caseta won’t work as a traditional 3-way switch but it does have a wall-mounted battery operated “Pico” remote that can replace the second switch and work as a wireless 3-way.

The next consideration is how reliable the switch is. Lutron and Leviton are the gold standards of regular switches and their smart switches are no different. As mentioned above, Lutron’s Caseta line has the additional advantage of not needing a neutral. Homeseer’s Z-Wave switches are also of high quality. These switches are all a bit pricey at $45+ a piece. Stepping down a price level into the $30 - $40 range we find the Zooz Zen series which is great for installation as mentioned above but has some annoying quality issues. The screws for the terminals work a bit weirdly, when turning it on from the other end of a 3-way switch, the relay is a bit loud and slow, and some people have complained of dead switches. However, Zooz’s customer support is top notch and will be very helpful with troubleshooting or replacing your switch. Inovelli’s new line of switches also falls into this price range and the jury is still out on whether the quality will be as good their older switches (which was excellent). Their customer support is also amazing and this has been my go-to company for switches. GE has a switch in this price range that many people are happy with as well.

A typical 1 LED smart switch
Lutron Caseta Dimmer
Next let’s look at how the switches… look. Normal light switches are bistable; when you push the top, it stays in until you push the bottom. Toggle switches are similar, you can flip them up or down and they stay in that position. Smart switches, however, are always in between. When you press the top or bottom of the paddle, they click in for a moment and then pop back out to a neutral position. This means that you can always rely on pressing the top of the switch as “on” and the bottom as “off”. In many dimmers, holding the top of the paddle brightens the lights and the bottom dims. This can be a little confusing for people expecting the switch to stay pressed. In my house, my family would press the top and hold it because it didn’t stay pressed and activate the dimmer. Eventually, everyone learned to “click” the switch instead of holding it but it was a frustrating few weeks. Zooz, Inovelli and GE switches have a little LED on them to help you find them in the dark but placing them next to regular switches calls attention to this difference. The GE and Inovelli also come with an extra almond paddle to swap out if that matches your decor better. The Lutron Caseta, Homeseer and new Inovelli switches have multiple LEDs arranged vertically to visually represent the dim level of your lights. One other note about Caseta switches is that they don’t look like your regular switches at all; some people like them but some hate them. Make sure you like the look before buying! Of course if you need a no neutral switch, you’re stuck with Caseta until the new Inovelli’s ship.

New Inovelli with LED bar
Finally, each switch has a slightly different feature set. The GE, Zooz, and Inovelli let you control when the little LED lights up; never is also an option. The Homeseer takes this a step further and lets you programmatically control its LEDs to show status and alerts from around your smart house. You’ll need some more advanced knowledge of smart home programming to make use of that feature though. We’ll talk about it in another post of course. Caseta requires a separate hub to remotely control it and also offers the ability to pair with Pico remotes. These are battery operated remotes that look just like the switch - you can mount them anywhere. They are often sold with the switch for only $5 extra. Scene control is another great feature to have. This allows you to control multiple lights in your house with double or triple taps of your switch. The Inovelli (advanced switch) and Homeseer are the only switches in this bunch that support this. The GE does support a double-tap to trigger a scene but not as flexibly as the others. The Zooz does support coming up to full brightness when you double tap the on portion of the switch but not full scene control. (Update 5/15: the newly released firmware for this switch enables scene control)



(Coming in June)
Approx Price
$38
$37
$32
$45
$55
Installation
Works without neutral
No
No
Yes*
No
Yes*
3-Way works with existing switches
No
Yes
Yes
No
No
Reliability
Quality (1 - 5, 5 best)
3
3
4
4
5
Aesthetics
Looks like regular switch
Yes**
Yes**
Yes***
Yes***
No
Has matching remote
No
No
No
No
Yes
Single Blue Status LED
Yes
Yes
No
No
No
Features
Dimmer Status LED
No
No
Yes
Yes
Yes
Programmable Color LEDs
No
No
Yes
Yes
No
Insanely responsive customer service
No
Yes
Yes
N/A
N/A
Needs additional Hub
No
No
No
No
Yes
Scene Control
Yes
Yes****
Yes
Yes
No
Energy Monitoring
No
No
Yes
No
No

* for loads greater than 25W
** has blue LED under rocker switch
*** has vertical strip of LED indicating dimmer level
**** requires the newly released firmware

One thing to be aware of is the distinction between an on/off switch and a dimmer. Dimmers are meant to control lights and can change the brightness setting of a bulb if your light bulbs are dimmable. However, do not use dimmers with things like fans or motors - these devices will not be happy with a dimmed circuit. Most brands offer both a dimmer and on/off model of their switches so make sure you are buying the right one for you scenario.

Most switches in my house are the previous generation of Inovelli switches. They provided good quality for a decent price. I have a few Lutron Caseta switches where neutrals aren’t available, even though it requires me to have a Lutron SmartBridge running. There are also a few Zooz switches in spots I needed easy 3-way installation. I’m looking forward to trying out the new Inovellis once they become available. They seem to have the best of all worlds: easy installation, no neutral required (but can use one for small LED loads), a programmable led bar and energy monitoring… and somehow, the lowest price! Which switch are you considering for your smart house project?

Update 5/15: Some readers have pointed out the the GE Z-wave plus models do support scene control. Additionally, the newly released firmware for Zooz switches enables this feature as well!

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