The Final Word in 3-Way Smart Switch Wiring (at least from me)

[@ChadAmI80]

You are so awesome! No, seriously!! I was searching on how to properly wire a three way switch with the power coming into the same switch box as the light feed wires and couldn't find an example online. You just saved me so much time from trying feed power into the other 3 way switch box. And now I also learned that I can easily add the shelly to this circuit in the future too.

[@michaeloneil5452]

Dr Zz. I love the videos. You are the go to channel for home automation videos. Love it. I do have a comment for the 3rd scenario. IF (big IF) you have power at both ends of the 3way wire. Then you can switch the wiring diagram to scenario 1. Switch 1 originally has the power, switch 2 has the line to the light. If you get power to switch 2, then disconnect the power at switch 1 and only use the power from switch 2. The new common (black) wire from the circuit breaker at switch 2 will be the black wire to switch 1, connect to black screw at SW1. connect red and white to the other SW1 terminals. SW2 Black screw will go to the Shelly SW terminal. the red and white connect to the other SW2 terminals. The common or black wire from the circuit breaker will also need to split between the Shelly Line (L) and Input (I) terminals. Now you have time left to get the Huckleberry automated.

[@phankins11]

Old video, but very well done, great help. My house was built in 63 and the wiring has seemed to make no sense... this helped greatly! Thank you. My three ways are scenario 1, power in at the switch. I am using Shelly 1 Mini Gen 3s. and the wiring is the exact same as above, with the added benefit of the Gen 3s having Bluetooth proxy.

[@maarten9844]

0:55 Scenario 1 6:47 Scenario 2 10:19 Scenario 3 (USA way) 15:25 Scenario 4 (Wireless option)

[@bmurphy88]

This comment confused me because I’m in the US and my three way fits scenario 2

[@mike1627]

I know you probably don't read all these comments but THANK YOU for this video. Your scenario 2 with the Shelly helped me out immensely!

[@kingipra]

This is awesome. I'm in a new construction and my 3 way switches were wired like the you described in Scenario 3. Thanks for shedding some light on this.

[@aaroncake]

The term you are looking for on the extra contact (red wire) is the "traveler".

[@DrZzs]

Thanks Occasionally I'm terminologically challenged.

[@richardburguillos3118]

Nicely done... Sooooo do ya have this for a Shelly Dimmer 2? Thanks

[@PeterPetersNL]

In The Netherlands you aren't allowed to have separate circuits - that is behind different breakers - end up in the same box. So you would have both neutral and line connections connected to the same breaker anyway. On a separate note: we usually only have two wires between the switches. One switch is fed the line. The other connects to the line-in of the light. The neutral is with the light. Usually there will be a line there too. Like the top diagram on nl.m.wikipedia.org/wiki/Wisselschakeling. As you can see you can also add more switches without much complexity.

[@DrZzs]

That is freaking Genius! That's it! I'm moving to the Netherlands!

[@NathanKrick]

There is another solution for n-way switching that is worth talking about that works when mains power and output to load are in two separate boxes. This is a much safer option than #3 in the video. First, replace all the n-way switches with momentary switches (you can convert a standard switch to a momentary switch for free). Next, use the your white neutral wire for neutral through the entire circuit (just pass it through each box). Use one hot/traveler wire as a hot wire (I use black), and the other hot/traveler wire to carry the switched momentary power (I use the red wire for this). Attach the black and red wires to each switch and continue each wire to the next switch in series connecting black to the bottom pole and red to the top pole. In the box with the load wire, use the black hot wire to power the Shelly and provide power to the "I" port. Attach red to the "SW" port. Attach "O" to the light/load and "N" to neutral (white). Last, after powering the circuit up, configure the Shelly app for momentary switching. This method should work for any n-way configuration and provide a safe way to do n-way switching with any number of switches where the mains power and load output are not in the same box.

[@DrZzs]

Thanks1

[@NathanKrick]

@@DrZzs I know this video was your final word, but it might be worth making a "final final word" that includes this momentary method and says not to use method #3 unless the other power source is on the same breaker... Hate to have people see magic smoke when there is an alternative, safe method.

[@steveringwood2224]

In circuit 3 there is a way to use the sonoff. Since box 2 needs/has a separate power feed, in box 1 you could cap the incoming power and convert the circuit to the first circuit you show.

[@DrZzs]

Very true! That's the way I did it in the very first 3-way switch video I did a long time ago. That would be my choice over mixing circuits like that 3rd method. Like I said, I really don't like that method, and I'm usually pretty cavalier with my installs.

[@chrislazaris]

Sorry but how can you convert circuit 3 to circuit 1 without having three wires connecting the two switches? Do you crisscross black and red wires to do the trick? Is there any other way circuit 3 can be usable with sonoff? I've also seen this solution utilizing a relay: itead.freshdesk.com/helpdesk/attachments/11052663458

[@bobtelco]

thanks, I just was able to complete my project today thanks to this video. I was stuck with option 3

[@kingipra]

I was stuck with option 3 as well. Wish there was a way to get the app to register the current state of the light when using the switch.

[@YalcinAy-y1d]

Amazing!!! This is exactly what I was looking for! Thank you! Do you know by any chance if this setup also works for aqara T2 relays!

[@TenTwennyDollaBills]

The problem with installing a SONOFF or Shelly in a light fixture is they are likely going to be in your attic. Two sources of heat when installing in an attic J box or a light fixture - the attic heat and heat from the light. These would far the operating temperature of both of these devices both are specificed to operate at a maximum temp of 40C (104F). Only way you can get there is with a conditioned attic AND something that doesn't use a bulb and emits light downwards (like wafer light).

[@fin3125]

I have scenario 3 but no power with the wire out to light. Really need a way for that.

[@nathanpearson4600]

Idk if I'm doing good or just dumb but because I use home assistant my 3 way switches are all hooked to a esp 01 not mains when you flip the switch it runs a automation to turn on or off my smart bulb. I also have very old wiring in my house so there is no neutral wire so I just used a wire nut to keep the socket power always on. Works good for me and then I don't have to worry about kids playing with switches and frying out my cheap-O- Walmart bulbs.

[@DrZzs]

Whatever works man!

[@Growla]

I have read that the Shelly 1 may have to be reset regularly. Why and how is it done?

[@pistonbroke5405]

love the speed of the pcbway ad next you'll be sounding like Alvin the chipmunk

[@DrZzs]

ha! It's at 1.25x speed. I didn't think anyone would notice! You are good!

[@digiblurDIY]

You know we would notice. :)

[@OldCurmudgeon3DP]

@@DrZzs It's used in many a commercial on the radio. Familiar sound.

[@anthonyd4238]

🎤🎼🎼meeee, I wannnt a hooolahoop

[@rdy4trvl]

So on the wireless option with Shelly, would it be possible to simply wire one relay ("the ruler") to the lights and have the other switches(+ relay?) communicate wirelessly to "the ruler" via wifi?

[@sammyboyproductions]

When are you going to do a video on intermediate light switching?

[@shawnd567]

I just realized I have the 3rd scenario 🤦🏾‍♂️ & have a sonoff mini. There's gotta be a way but I can't think of anything other than somehow using one of the 3 way neutral carry a load and mark it with black tape and then grab neutral from a different source going to the light? Is that code? Is it safe?

[@joconnor5241]

Can you run two 3-way stitches off the Shelly 2.5? Ie. 2 gang each with 3 way wiring?

[@thomasburkholder817]

sir is there a way to use Sonoff mini in existing 3-way circuit that has light in on first switch and power in on 2nd swith. all my 3 ways are wired that way

[@bibbygkkm]

is there a maximum length, for the sonoff mini, between the mini and the switch which changes the state ?

[@aliallawati2859]

Hi @drzzs i have three way switch in my stair case both ends and three lights in the staircase. 1 at Star of stair case, one and middle and one at end. GF switch has the line in (phase) connected to common. two wires travel from gf to the other end switch(1st floor) where L1 is connected to L1 and L2 to L2. From L of the 1st floor switch phase goes to lights. Nuteral is direct from ceiling. I have nuteral and additional phase in 1st floor that i can make use of. My question is. How to wire sonoff siwtch to work as two way on 1st floor switch socket

[@JonSnyderfudge]

Good informational video. What is the easiest way to tell what scenario you are in just from the light gang boxes?

[@rich22111]

Need help please. My got white and red for left and right similar like yours first set up. Then it got a red to the common, from the same red cable, the black just connected together with other black cables from other lights cables. On the other switch, it got the white and red like yours, but a single red wire connect in the common of the switch. What should I do? I believe it need to do from the 1st switch, right? But not sure how?

[@saotekwong3276]

I think I have a solution for scenario 3. I haven't tried it but I think it will work. here is the plan. replace the "main" 3 way switch (the one with line coming in) with a normal switch. and use one of those smart switches with normally open and normally close function. Too bad I can't post a picture of those. and use those NC and NO port as traveler to the other switch.

[@regular_goof]

Im lost. I have one L? brown cable and two black cables coming to both of the switches. Than the light only has one L? brown cable and one yellowgreen ground cable. Any help ?

[@neilbrookins8428]

Everything in the video looks good and accurate. The only misleading fact is that the traveler wires between the two 3-way switches do NOT have to crisscross. In fact if I was making a video I would place a 4-way switch in-between the two 3-way switches thereby creating a 4-way switch configuration. In this way we can demonstrate that the wires between the three way switches can either be crisscross OR straight through depending on the 4-way switch’s position.

[@Whatarewefixingtoday]

So, scenario 3 looks ok to you?

[@neilbrookins8428]

Sir GoodEnough considering that the Shelly 1 fully supports 240v on the power supply side and dry contacts on the relay side for uses such as controlling a low voltage device, Comparing that to scenario 3 where there is a 240v difference between relay and power supply (if supplied on different legs) seems similar. That all being said. I do agree with another commenter here that the best solution if you are running new power line to the Shelly box it would make sense to disconnect power to the light from the original source and simply use the new source. That way there is only one supply leg and no 240v potential. But for a device designed for 240v and 120v I still think it should work either way.

[@richardstratman2107]

Great of video - it seems unless you need scenes shelly might be the best way versus regular smart switch? - Keep them coming!

[@EpsilonFilms]

In scenario 3, you could just buy a regular smart switch with the corresponding add-on (For example, Leviton DZ15S and DDR0SR-1Z). More expensive yes, but you're not left with the incomplete solution you have here. The statement that "most smart switches can't do this" is a bit misleading.

[@ivanfjunior]

I have installed sonoff in the first configuration, power and light line out in the same junction box. It works as expected, however the light is blinking every minute or so. Have anyone experienced this?

[@cysix4939]

Lol... reminds me of the video I did back when. Posted a link to this one on my video description. Keep up the excellent work buddy.

[@DrZzs]

I remember that video! Very helpful :)

[@GabrielDIYTechlife]

@@DrZzs min 13:25. On the shelly app, you just have (on the shelly 1 settings) to set the "Button Type" to "Edge Switch" and it changes the state on every hit of the switches. I have this exact setup working perfectly :)

[@newby2224]

Hi there, Can this be done with no Neutral? so 2 way (outside USA) but only live wiring.....thanks

[@acuacu8611]

You can do that with a Shelly 1L but not the Shelly 1

[@alexiasg.1107]

Would you able to help with shelly Dimmer I have a 3 way light switch

[@kml9434]

I am working on my stairs, I am frustrated, I have tow lights upstairs and down, I've reached that it's working somehow fine, but when I turn off from downstairs Shelly 1pm loose connection, it's connected in the box upstairs!!

[@sublime24882687]

Hello Dr. Zz is it possible to use a sonoff tx t2 us switch for a Power to Light Switch with Fixture Between Switches setup? If not can you recommend a 3 way smart switch that can also be flashed with tasmota?

[@Vendoization]

Dr. ZZz I have a usual situation with MOES 3 way in the main hub where line comes in and traveler comes out and from traveler switch it goes to the light. It works on many places in my house with MOES 3 way. The 3 way works mechanically OK as it SHOULD with on/off on both sides. BUT the smart switch for some reason is not registering when light is toggled from the traveler switch. I have checked continuity etc. can not figure out what is causing this issue. Have you seen this?

[@DrZzs]

I did see that when I had two circuits involved. One for power to the lights and another to power the switch. Doesn't sound like that's your issue though. Sorry. Not sure why that would happen.

[@scj1313]

Doesn't this approach put the load on the second circuit vs the first circuit as it was originally designed? The original circuit is wired to the switch input of the Shelly appears to simply be a trigger.

[@EpsilonFilms]

I had the same thought... he's tying in the lines from two different circuits, which doesn't sit well with me. Maybe against code? I'm not sure.

[@carlcallenburg7898]

Great Video! BUT at 15:36 you talk about something I have been searching for without luck Will you do a video on how to make one Sonoff talk to a second or third Sonoff without using the home network or internet but rather using the server that Sonoff comes from the factory with. I do not have internet at the location I want to use these at. This is a very large building with the lights controlled at only one door. There is NO 3way wiring to other locations. I was hoping to use a Sonoff mini or basic to control the lights at the current switch, then install and power other Sonoffs at the other doors that would trigger the control.

[@ColePanike]

Without internet you've going to have a really hard time. The factory Sonoff firmware relies on internet connectivity, so that's hard out. You can't do it with Tasmota either as they require at least a wireless router. If you had a router, even without WAN, you'd could still do it that way though. If that's not an option, you're really out of luck, unless you can program these yourself. If so, you COULD (in theory) write some custom logic that would have the device connected to the lights act as an access point and connect the others directly to it. Then you could pass messages directly to the host unit to the light on and off.

[@ColePanike]

See this question for a similar situation: github.com/arendst/Tasmota/issues/5613

[@carlcallenburg7898]

In reply to "Cole". Thanks by the way. I should have said. I could do set up the Sonoffs at my home with the internet but the place I need to use this does not have internet. I could add a router, but I would need information on how to make that work with the sonoffs for this project. The one work around (or other solution) is I could use a Sonoff RF, I get one that came with a small button unit. I could put the at the other location. But I will would rather use two basic or mini units so they get power and not batteries.

[@ColePanike]

@@carlcallenburg7898 well, let me ask you a couple questions then. Do you understand basic networking (IP addresses, what a LAN is, and how to configure a router)? Can you flash new firmware to the Sonoffs? Could you write some new software for the devices and load it on them? There's more than one way to skin this cat, but what you're trying to do is going to require some effort and know-how.

[@JohnBaxendale]

I think the fact that the Shelly can use a 230v input is a *huge* difference to the Sonoff, it means the Shelly can be installed inside a light fitting, versus the switch box and will still function. The Sonoff could not be used in that way. I'm also pretty sure that given a much longer run of wire (eg: where you have upstairs and downstairs 3-way switch setup controlling a hallway/landing light), the resistance over the cable length would mean 3.3v would not be sufficient, especially on older installations. I'd have to check this, I'm not 100% sure.

[@huubboegheim9299]

Am i right that there is one major difference between the Sonoff and the Shelly, wich is: The sonoff needs the wires from the switches both to come in seperately (the are i no way connected to the actual power) and the shelly just needs the 1 commen contact and the other other commen is connected to the power or +. This would make the sonoff harder to connect as you need an extra wire from the switch that would have the +. Hope you can understand what i am trying to say, not to good at typing in english

[@DrZzs]

I think you have it backwards. The Shelly needs an extra wire if you want the relay to switch the same circuit that powers the shelly. The sonoff relay always switches the circuit that powers the sonoff. Hope that helps.

[@jordancobb509]

The Sonoff can do the same trick for scenario 3, with a ESPHome and some programming.

[@kyermichael]

Mr. Doctor Sir, first - as an insomniac smarthome diy nerd, i love your videos, keep up the great content! a question for you - i have sonoff minis flashed w/ tasmota.bin on both regular switches and 3way switches, and unlike in your video where it is instantaneous, my sonoffs respond very slowly to the physical switches (2-6ish seconds for the state to update). any ideas? my 3way is wired exactly identical to yours, so i am stumped after trying to google-fu the answer.

[@kyermichael]

I want to reply to my own comment to give some information that may be helpful to others: I figured this out! So the problem was somehow a result of flashing OTA, and flashing OTA sucking. When I did the OTA procedure, since there wasn't enough free memory to directly write tasmota.bin (aka the old sonoff.bin) I had to first write tasmota_minimal.bin (aka the old sonoff_basic.bin) and then use the web interface in Tasmota itself once the device came online to upgrade to the tasmota.bin firmware. After loading tasmota.bin, this was always extremely laggy, not only in my 3-way switching setup with physical switch toggles, but laggy from the device's web console as well. Unfortunately, I never found a way to fix the lag.... ...But since not only did my stock Sonoff Mini modules not suffer this lag issue, but also because I noticed that the tasmota_minimal.bin had no lag when toggling from the web interface before I OTA flashed tasmota.bin, I had a hunch that something just wasn't sitting quite right with the way the firmware was written to the flash using the OTA method. So, I decided to get all of the necessary implements to try re-flashing the offending modules via USB. I first erased the flash using esptool, and then just for good measure wrote a blank bin file to the module to ensure that the flash was erased completely (link: www.pratikpanda.com/wp-content/uploads/2016/05/blank_1MB.zip). I then wrote the exact same tasmota.bin to the flash, and LO AND BEHOLD the lag disappeared and everything was perfect and peace returned to the land. tldr; f*** OTA, serial flashing is a bigger PITA to do, but it is well, well worth it.

[@kurtbrown7504]

Can someone help me my house is wired differently than any of these I have 3 switchs in my living room two have 3 wires red black and white the third switch has two white and two blacks

[@mikebullough8626]

What about a circuit that has 3 switches involved?

[@DrZzs]

oh sure... now I'll be making another video! :) Really though, there is another kind of switch with 4-poles that is made to go between two 3-way switches. The wiring looks like this: www.electrical101.com/4way-switch-wiring-using-nm-cable.html The concepts about the smart device needing power and being directly connected to the lights still apply. Hope that helps. I think I have a 4-way switch lying around somewhere. I could probably get it out and set up a demo.

[@pplum81]

When you set the button type to edge switch on the shelly's webpage, your toggle issue will be solved

[@ivanfjunior]

I have tried the 3 available configs, including edge switch and follow switch. Still facing the toggle issue. Could I have a defective sonoff?

[@pplum81]

Hi Ivan, I'm reffering to the Shelly device. Unfortunately I don't have any experience with the sonoff switch device.

[@jonnyawright]

@@ivanfjunior I've had nothing but issues with the Sonoff on multi way switching and I think it's due to voltage drop across the circuit. The Sonoff doesn't have mains voltage across the switch wire, but the Shelly does

[@ivanfjunior]

@@jonnyawright thanks for the reply!

[@Linsazxxx]

Hello sonoff mini can be setup as two gang swicht?

[@DrZzs]

yes. dl.itead.cc/mini/Two-way-Contro_750.jpg

[@martinparkinson935]

Thank you soooo much for that video!!!

[@cskhard]

Thanks! This was super helpful and interesting!

[@nigelholland24]

Still cannot get my head around it with uk wires

[@DrZzs]

Which way is yours wired? I'm guessing the Line/Neutral is in the ceiling only. Does it come in between the 2 switches? I'm sure there's a way. If all else fails just make it a normal Single-switch setup then use another smart switch to do the wireless method. Let's get it worked out for you Nigel.

[@nigelholland24]

DrZzs I have done the single switch with Shelly. I only have 1 3 switch and 3 bulbs configuration so really not going to play with that one but thanks for the help

[@ecoterrorist1402]

You will probably find that you don’t have a neutral at the light switch anyway.

[@nigelholland24]

@@ecoterrorist1402 I haven't it's in the rose

[@de4323]

Simply perfect thanks

[@pvigoyoutub2009]

Amaizing Tutorial! Great job! Adios!

[@markmacherey4744]

I have a fairly good grasp of these configurations but when I open up my switch box's, all the wires are painted white (face palm)

[@ferencszabo3504]

The best part is when we need to sort out the same colored wires! 😁, i got one of those power sensing gizmos from China, so no more guesswork, and surprisingly it works

[@PeterPetersNL]

If they are just painted can't you remove the paint at least a little bit?

[@techguy3507]

Thanks

[@wolf3five]

You did a back feed 3way theres one more may to do a 3way that is not back feed

[@electroman982]

As a important note here...@7:00 that wiring method is a NEC (code) violation due to not having a neutral between the switches. That may not seem like a big deal...however as the load increases the electrical radiation between the switches increases and long term exposure ISN'T a GooD thing!!

[@rafmil13]

Thanks Master.

[@Whatarewefixingtoday]

Scenario 3, this is BAD! You can only do this if the 110 powering the shelly is on the same phase as the light. Otherwise the hot that comes in to power the shelly and the hot it is switching may collide in a poof of magic smoke... .

[@digiblurDIY]

Indeed as it could cause other issues. I would highly recommend a real 3 way switch in his scenario like the Martin Jerry, Moes or Etekcity 3 ways that have travelers.

[@Whatarewefixingtoday]

@@digiblurDIY Agreed, in this scenario spend the $25 and buy a real smart 3 way switch, and replace the one where the power comes in with that. Don't do #3...

[@OldCurmudgeon3DP]

Maybe I can pull a Tim Allen and rewire it. Without the smoke. Decora types have 0% WAF.

[@Whatarewefixingtoday]

@@OldCurmudgeon3DP If you pull a wire from the same source as that coming into the 3 way circuit, Like he did in the video, you are ok. It means pulling a wire over, though. I would not come from a different circuit...

[@OldCurmudgeon3DP]

@@Whatarewefixingtoday nothing is ever easy eh. Or, since wires would need to be pulled anyway, just move the light into the source box and be done.

[@RiadAmastha]

Hello, your videos are great. I was able to install the SONOFF Mini using this video on a 3 Way Light Switch. I just have a scenario that I need your help with. I bought the Sonoff Mini and would like to install it in a 4 Way Switch scenario. My wiring is exactly as show here (4-Way Diagram - Option 1) www.support.getzooz.com/kb/article/211-4-way-diagrams-for-zen26-and-zen27-switches/ . I tried to use this video but when everything was connected at BOX 1 to the mini, Only the SONOFF mini was able to turn on and off the lights. The wall switches did not work. Any thoughts would be appreciated.

[@donny_bahama]

“The first thing you need to determine is where does the power come in from the circuit breaker and where do the wires go out to the light” OK... but HOW do I do that?

[@ChrisWalkup]

@Donny Ferris This video should help with your question: kzbin.info/www/bejne/jqGXd4qAh997mtE

[@Hasses67]

Omg.. ?????? still confused, sorry Doc not your fault. I have to see this video a 100 times more!

[@DrZzs]

ha! Sorry man. It's not easy to conceptualize. :)

[@mastershake156]

*engagement*

[@DrZzs]

Hello Jimmy

[@mastershake156]

@@DrZzs hello dr. I have this rash. Can you take a look at it?

[@Whatarewefixingtoday]

@@mastershake156 Take a bite out of an extension cord. The pain will make you forget about the rash.

[@mrnix1001]

I consider myself a fairly intelligent person, but these switch setups confuse the hell out of me. I've watched more videos on this subject than I care to admit to but for some, god unknown, reason, I can't wrap my (tiny, apparently) brain around this. I'm just hoping I'll finally grok this via osmosis, hence the reason I continue to watch these things.

[@JohnBaxendale]

This diagram, for me, makes it super simple: en.wikipedia.org/wiki/Multiway_switching#/media/File:3-way_switches_position_1.svg

[@OldCurmudgeon3DP]

Stupid US elek-chickens. I have a mind to rewire mine to something that works. I've not seen a 3-way switch that's not Decora that also isn't Z-wave. Decora doesn't make 1% WAF.

[@kevinpinheiro2485]

I have Shelly 1 and I wanted to set it up with home assistant and node red such that the switch is separate from the relay. So I can put a delay in between the two action. Any idea how to do this ?