4 Best Smart Switches That Work With No Neutral Wire

My house was built in 1909. It still has pieces of the original knob and tube electrical wiring nailed to the floor joists in the basement.

Thankfully, the electrical has been updated since then.

Unfortunately, I still have a few switch boxes that don’t have a neutral. That means that the vast majority of available smart switches won’t work in those boxes. However, I scoured the internet and found some that will.


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What are the best smart switches that work without a neutral?

Here are my two main requirements for a no neutral smart switch:

  1. Works with no neutral – Well, duh.
  2. Works with LEDs – Any smart switch I install needs to work with LED bulbs. I quit buying incandescent bulbs years ago.

Believe it or not that narrows down the field quite a bit. There are a few other smart dimmers that work with no neutral, but I didn’t list because they don’t work with LED lights.


Lutron Caseta Dimmer Switch

If reliability is what you’re looking for, then look no further. I’ve been using Lutron switches for over two years, and I don’t remember a single time when I pressed the button and the light didn’t come on. I’ve tested a number of other smart switches, and Lutron is the only one that has NEVER failed me.

The dimming performance is also exceptional. Even with LED bulbs (must be marked as dimmable), the lights can be dimmed to almost nothing.

However, the Lutron switches will be the most expensive of the group. If you haven’t bought any Lutron products before, the best way to save a little money is to buy a starter kit bundle.

Also, make sure you get the Lutron dimmer switch. The standard Lutron on/off switch will NOT work without a neutral.

Read more: Lutron Caseta Review


Inovelli Red Z-Wave Dimmer Switch

If you are a die-hard home automation geek, this is the switch you want.

This switch is packed with features. You can control multiple scenes, smart bulbs, and even setup smart notifications using the onboard LED. The setup takes quite a bit more work than the Lutron or C by GE systems, but these Inovelli switches are way more powerful from a home automation standpoint.

Just like Lutron, make sure you get the dimmer switch since the on/off switch will NOT work with no neutral.

NOTE: These do require an extra part (Aeotec Bypass) if you use them with no neutral and the load is less than 25W. Most single LED bulbs are under this threshold. If there are multiple bulbs in the fixture, the total load is the sum of the load of all bulbs.

Read more: Inovelli Red Series Review


C by GE 3-Wire Switches

The C by GE switches are a great all around option. They are easier to setup than Inovelli and cost less than Lutron.

They connect directly to your WiFi router so there’s no need for an additional hub. In addition, you have the option to install C by GE smart bulbs in your fixture to add color lighting to your system.

You can choose from an on/off switch, a dimmer switch, and even a motion-activated dimmer switch (make sure you get the switches labeled “3-wire switches” – not “4-wire”).

Each switch comes with an bypass adapter for low power bulbs, which is both convenient and cost-saving. It simply screws into the socket before the bulb. The only negative is that it adds an extra inch or two of length to the bulb which could cause problems in an enclosed area.

The C by GE switches will integrate easily with Google or Alexa, but they currently don’t play nice with more advanced hubs like SmartThings or Hubitat.

Read more: C by GE Review


Shelly 1 Relay

This solution is a bit different than the other options, but can work just as well. In fact, for many people I think this may be the best solution.

Here’s how it works:

If you don’t have a neutral at the switch, then you will have a neutral at the load (light fixture).

Therefore, you install the Shelly 1 relay behind the light fixture where there is a neutral.

You keep your existing switch(es).

Since the Shelly is installed with a neutral, you don’t need to worry about needing a bypass for small loads.

The Shelly products are WiFi so you won’t need another hub. You can choose to use them with cloud integrations or without (local control only). Additionally, the Shelly app is quite versatile. You can set the relay to work with an existing toggle switch, momentary switch, or even 3-way switches. And if the Shelly app isn’t good enough for you, you can go “full geek” and install custom firmware.

Of course, Shelly is not the only brand that makes mini smart relays like this. The truth is I haven’t tested any others because I have no need. The Shelly products are so versatile, reliable, and reasonably priced that I have no reason to try anything else.


How do you know if you don’t have a neutral?

Here’s an easy way to check:

If you open your switch box and you see two white wires joined with a wire nut (not connected to the switch), you can be fairly sure your switch has a neutral wire. You should be able to install any smart switch.

A switch box with no neutral loop will usually only have three wires (see image below). Two of the wires will be the current carrying wires that power the light. They will usually be colored one black and one white (potentially with black stripe or marked with black electrical tape). The third wire should be the ground wire and is usually colored green or bare wire.


Four options if you don’t have a neutral

If you want smart control of your lighting, and your home has switch boxes with no neutral, you have 4 options:

1. Buy a smart switch that works with no neutral

When smart switches first came out, it was hard to find a good “no neutral” switch. But manufacturers responded to demand, and now there’s a handful of good ones available. Between the three listed (Lutron, Inovelli, and C by GE) in this article, you should be able to find one that fits your needs.

2. Install a smart relay switch at the light fixture

In any installation, either the light switch or the light fixture MUST have a neutral wire. Therefore, if there’s no neutral in your switch box, the light fixture will have one.

There are several compact smart switches which can fit inside electrical boxes and light fixtures. So, if you don’t have a neutral at the switch, you can use one of these compact smart switches installed at the light fixture.

With one of these smart switches, the existing switch does not need to be changed and will continue to work.

I’ve used the Shelly relays and they work really well.

3. Buy smart bulbs instead

You don’t necessarily need to buy a smart switch. Instead, you could buy a smart bulb.

Most home automation experts recommend smart switches over smart bulbs. But, if you want easy installation and the option for colored lights, buying bulbs could be better.

However, that introduces the new problem of figuring out what to do with the existing switch (here’s some ways to solve it). When someone decides to use the wall switch to shut the light off, the power to the bulb is cut, which means it will stop being a smart bulb until you turn the switch back on.

4. Add a neutral by pulling new wires

A neutral wire can be added by pulling an additional conducting wire between the fixture and the switch. This option is probably the most work and most unnecessary.

It can be done, but pulling wires through finished walls can be a real pain, especially if you don’t have the proper tools. Sometimes it might even require cutting into drywall, which then needs to be patched and painted. You could certainly hire an expert to get the job done, but it will cost you.


What is a neutral wire?

If you’re going to be installing your own smart switches, you will be working with some potentially dangerous wires, so it’s probably a good idea to know what you’re dealing with so you can avoid making a stupid mistake.

In order to fully understand what a neutral wire is and why we have it, you need to have a basic knowledge of how our homes are wired.

Typical electrical transmission lines in the United States have high voltage electricity (13.2 kV which equals 13,200V!). Before the electricity can be used in your home, it needs to be converted to a lower voltage. This is done using a device called a transformer (represented by the squiggly lines in the image below).

electrical diagram showing typical step-down transformer for U.S. homes

NOTE: Alternating current (AC) does not have polarity. Instead, it has phases. I used the + and – symbols to represent the different phases.

The transformer converts the incoming 13.2 kV electricity down to a usable 240V. Notice that the voltage difference from end A (+120V) to end B (-120V) of the transformer is a total of 240V.

Also notice the transformer has a line coming from the center which has a voltage of 0V. This is the neutral. Since the neutral has a voltage potential of 0, it is significantly safer to work with than the “hot” wires A and B.

Looking at the diagram above, you should be able to see there are three ways to create a circuit:

  1. Connect A to neutral = 120V
  2. Connect B to neutral = 120V
  3. Connect A to B = 240V

Most wiring in your home is 120V (either 1 or 2). Certain applications that require a lot of power, such as a stove, are usually wired for 240V (3).

What does it mean when a switch has no neutral?

According to the previous section, every 120V circuit in your home has both a hot wire (A or B) and a neutral wire. So, how can it be that some switches “don’t have a neutral”?

To HAVE a neutral, we want the line voltage to come to our switch box first. Then, from the switch box another loop goes out to the load (light bulb or whatever). The diagram below shows this configuration (this circuit HAS a neutral).

electrical diagram showing standard switch with neutral wire

The case that everyone refers to when they say “no neutral” is when the line voltage comes to the light bulb first. Then, from the light bulb, another loop goes to the switch. This is shown in the diagram below.

The line voltage goes to the light first, then to the switch (no neutral)

Both circuits work just fine when you only have a standard mechanical switch. However, you run into a problem when you have a smart switch.

Why is no neutral a problem for smart switches?

In the diagrams below, the dotted rectangle represents a smart switch. R1 represents the load required to power the smart switch. That means there needs to be power running through R1 at all times. Otherwise, the smart switch will be unable to power it’s wireless communication.

Smart switch with neutral

Below is a diagram of a smart switch installed in the first configuration (with neutral). Notice that regardless of whether the switch is on or off, there is a clear path from line to neutral that includes R1.

electrical diagram showing smart switch with neutral wire

Smart switch with no neutral

Now let’s take a look at the second configuration (no neutral) with a smart switch installed.

Again, regardless of whether the switch is on or off, there is a clear path from line to neutral that includes R1. However, in this case the light needs to be included in that path. That’s not good because we need R1 to be on all the time but we don’t want the light to be on all the time.

The key to creating a smart switch that works without the neutral loop is to make R1 the perfect resistance. R1 needs to restrict the current enough so that the light bulb doesn’t turn on when the switch is off. At the same time, it needs to let enough current through so that the switch can power itself.

If it were as simple as making R1 the correct resistance to make sure the light can’t turn on when the switch is off, it would be a fairly simple problem to solve. However, due to complexities caused by AC power, it’s not a simple problem to solve when it comes to powering LED bulbs. That’s why the options are so limited for smart switches that work with no neutral.


Final Thoughts

If you have switch boxes without a neutral wire, there’s no need to panic. Several manufacturers have come up with smart switches that solve the problem. And, if none of those are what you’re looking for, there’s always smart bulbs.

35 thoughts on “4 Best Smart Switches That Work With No Neutral Wire”

  1. Stephane Boisjoli

    It seems everyone misses the obvious: Don’t put the controller in the switch box. Get something like “Micro Switch G2, DSC26103-ZWUS, by Aeotec with Pigtails”, put it in the light box, and it will control the light. Now, the problem I haven’t figured out is what kind of controller to put in the light box to switch the light. It may help to re-wire the switch to not actually switch and just provide the box with power.
    (When I used X10 stuff, they had a purely wireless switch [no wires at all], but I don’t know if that exists in the smart home environment yet).

      1. When the fitting has multiple bulbs, or when the switch controls multiple fittings. Ie Chandelier type with 5 candle bulbs, or multiple recessed lights in a kitchen (12 bulbs in my kitchen, all switched on together)

      2. The switches are pretty much a one time purchase and I’ve yet to have one die on me… Wifi bulbs on the other hand are expensive and seem to have a shorter life… I just wrote a poor review of the 6 tracklight bulbs I bought for about $45 that lasted about 4 months til the last one died… And then I just installed 4 led wif bulbs in my overhead fan… and found like other purchasers that the bulbs have decideed to not be Alexa compatible…. I’m still waiting for their techs to figure out why their webpage won’t accpt the password that I chose on their app… But mainly price.

      3. I did that, brought 6 lights for my kitchen. All C by GE, not off brands. It was horrible, the lights even though grouped together the would not work in sync. When I turned all off, one would remain on, go off several seconds after the others then 3 would come on after that it was a mess, reset them all a few times, ungrouped them, nothing changed. A few kept losing connection and would not connect to the app again until the bulbs were manually reset and that’s a pain in the butt. A smart switch is much more convenient, only one connection to worry about, not several. Plus GE doesn’t sell daylight brightness smart bulbs, not of the more reputable manufacturers do, the soft white “yellowish” brightness reminds me on when I was a kid. Tried other “off brand” smart bulbs and they all failed within a few months.

      4. It looks to me like the Aeotec switches suggested by Stephane all require a Neutral wire. So they don’t seem to fit the criteria. Am I missing something?

      1. These are cool switches but they are not compatible with LED bulbs – so unfortunately does not fit the criteria. GE makes a “C by GE” series that work well but they are not zigbee like these illumination switches.

  2. What about when I have a 240/220V switch (for baseboard heater) with 2 hots, a ground and no neutral? I only need a switch for this, not a thermostat.

    Thanks!

  3. Another option is Insteon Remote Control 2-Wire Dimmer Switch. This switch doesn’t require a neutral but you will need the hub too.

    1. Thanks, I hope it helped! The article is not written yet, but soon. I’ve been using the Inovelli switch for about 2 weeks and I love it. It has nearly everything you could want in a smart switch.

  4. I just connected a 3 gang smart switch with no neutral that worked perfectly fine with two chandeliers, but the third switch is for a series of spotlights (downlights) and once the lights go on they do not switch off though the switch is showing to go to blue from red, so it is taking the command to switch off but the lights won’t turn off! I tried installing another switch thinking that it was a faulty device but same problem happened. What am I doing wrong?!

    1. See the part about “the perfect resistance” in the blog post. I would suspect that the there’s enough resistance to power the two chandeliers off (incandescent lights?) in the two switches but not enough resistance in the third to power off the down-lighting in the third switch. The down-lights probably require less energy to power (i.e. LEDs?).

  5. Why cant they just make a no-neutral smart switch with a small battery in it? When the light is being used, the battery is recharged. Then when the light is off, the switch wifi runs off the battery. Its my understanding very little current is needed to run the wifi. I understand that going away on vacation the battery might die, but then just manually turn the light switch on to top up the battery when you return home.

  6. These roundups almost always miss Insteon’s 2-wire switch. Like the Lutron switch, it requires Insteon’s own hub/bridge if you want to link it to anything else, but it’s been around longer than nearly any of the other solutions listed here. Also expect to see a new 2-wire (though they’re calling it 3-wire, counting Ground for some reason) in the C by GE line soon.

    1. Thanks for the info! I haven’t used the Insteon system, but I did see the dimmer you’re referencing. I declined to add it to the list because they don’t appear to work with LED bulbs.

  7. I have alexa which I have just been using for basic lists and other bs. I am installing a smart switch in my bathroom. I also installed a exhaust fan that includes a bluetooth speaker built into the fan casing. Works fine. But it needs to be manually turned on. It also needs to be turned off from the switch. I want to have the switch controlled through Alexa. The problem is that every Alex switch needs a neutral wire. The connection presently is… power ( with neutral wire ) to Timer switch for fan. The Bluetooth speaker Switch takes the black from the fan switch and and goes up to the fan. If I add a Neutral wire onto the Bluetooth switch it doesnt work.
    HELP… is appreciated.
    Thanks

  8. What about adding a capacitor in parallel with the light bulb ? I’m not sure if that works with LEDs, a lot of smart switches I see on sale (with no neutral) doesn’t require hubs. I think that’s a huge plus if you’re able to connect directly to wifi instead of using additional gateways.

  9. My issue is that the wiring from the Pool Light (Pentair Intellibrite) runs to the transformer by the pool equipment, then just has simple in/out lines to a switch in the house, no neutral, or ground for that matter. You cannot use a dimmer switch on these LED lights or you will damage them. At this point, I have not been able to locate a simple On/Off Z-wave toggle that will work without a neutral. My other option would be to use a Z-Wave controller at the transformer and just leave the old 2 wire toggle on all the time. 🙁

  10. I believe the ‘without neutral’ diagram is incorrect (though I have unfortunately experienced some wired that way). In the diagram, the light socket is always ‘hot’. so even when the switch is open, there is power to the light socket. I dont believe this ever met code (nec). If you are changing a light bulb its decidedly dangerous. If the black hot wire goes first to the switch, then the light, then neutral is on the far side of the light, it will function correctly, plus the socket will not be hot when the switch is open – of course it will still be a no neutral condition.

  11. Hello,
    I bought the CE Smart Home Wi-Fi Smart dimmer light switch.
    My existing switch box does not have a red wire.
    Instead, I have 2 black wires going into the old switch and 2 white wires connected to eachother with a marret.
    Is it possible to wire in my new switch without the red?
    I don’t need dimming but I do need the wifi feature to work with my google home.
    Thanks

    1. It should work, but I can’t be sure without testing the wires. Usually the white wire is the neutral. If that’s the case, the two black wires (hot and load) get connected to the new switch and a third wire connects the white wires to the neutral terminal on the new switch.

  12. great info, i spent many hours and exchanges, trying to change a switch to a motion detector switch, the first room no problem, had neutral, the other 2 rooms no neutral, told to get a different model that did not require a neutral, but did not work, because it was also a dimmer. trying to light 2 fixtures with 3 t8 florescent ea. ea 32wt. is there a no neutral motion switch -non dimmer that will work

    1. This C by GE switch works with no neutral and has integrated motion sensing. However, it also has dimming functions which probably won’t work with the florescent lights. Regardless, you should be able to configure the switch for use as a simple on off.

  13. Hi, I like your suggestions and diagrams. A device I just got and I think is lovely is Shelly 1L. Works perfectly without neutral, so I think it does a good job at solving the “no neutral” smart lighting dilemma.

  14. As one other reader pointed out, your drawings of a non-neutral switch box are backwards. You would NEVER even consider switching the neutral side of a load, as it leaves the load hot all the time, and seeking out any path to ground.

    What actually happens in these cases is that the hot wire and neutral from the breaker panel go directly to the fixture box. From there a hot wire and white wire pair travel down to a switch box and are wired across the switch. At that point the white wire becomes a hot wire and must be taped with black electrical tape to signify that it is now a hot wire. Same thing in the fixture box. This way the hot power is switched before touching the load. And while not preferred, it is perfectly legal. The downside, of course, is that there is no neutral wire in the switch box.
    This is the best picture I could find to illustrate the no-neutral situation. https://mrelectrician.tv/light-switch-wiring-diagrams/

  15. I have an old house with only 1 box with a neutral, so I bought the Lutron Caseta with the hub. It was a great purchase and totally worth it. I thought about adding neutrals or gerry rigging something at each place I wanted to place a smart light switch, but why go through all the hassle. Investing $50 in the Lutron hub is totally worth it. Why go through the hassle and time suck it would take to make each switch box work with the other smart switches. In the end it would probably cost me more than $50 (the investment in the Lutron hub). Plus, the Lutron Caseta is the gold standard of smart switches and it is HomeKit compatible. To me it is a no brainer.

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