4-way switching without a neutral between Master and Auxilary?

The problem:

I am updating a 4-way switching circuit that has 14-2 (black, white, and copper) run to the 4-way switch in the middle. The boxes containing the switch for the line power and load contain a neural, but there is no neutral for the auxiliary switch replacing the 4-way switch. This is a likely scenario in older homes where electricians saved on copper by using 2-wire instead of 3-wire romex to a 4-way switch as long as the neutral completed the circuit elsewhere.

The circuit with a Master (GE 12724) and Auxiliary (GE 12723) switch works if the old 4-way switch is bypassed by tying the load (black) and traveler (white) wires together in place of the 4-way switch. But, this solution changes eliminates a switch in a prime location.

How can I functionally replace the switch in the middle of the circuit without fishing a new wire?

Prior topics:

I tried the forums and found a number of discussions that I thought would be relevant, but in the end didn’t solve my problem:

  1. Old wiring and Z-wave switch: No neutral: very long discussion going back to 2013, couldn’t find situation similar to what I encountered.

  2. 4-way switch with aux missing the neutral - This entry seemed like it would be the answer, but it was actually a case of ms-identification of where the line power entered in the middle of the circuit where the 4-way switch was located.

##Potential solutions:
These discussions lead me to 2 alternative solutions that I thought may work without pulling a new wire to the location of the 4-way switch without a neutral.

###Relocate Master switch and add a physical switch with programmatic control
Connecting the 2-wire from the 4-way switch to the line voltage and neutral where the Master is currently located (where power enters the circuit) would get power and a neutral to the location of the 4-way switch. However, this eliminates the traveler, so secondary control from an un-wired switch (i.e. a switch that is not wired into the same circuit) or scene controller would be needed to replace the current master switch. This would require the un-wired switch/control to programmatically control the lights through software running on the SmartThings hub.

This seems like the optimal solution, but brings up a few different questions:

A) What z-wave scene controllers are compatible with SmartThings that could take the place of a switch on the wall? Scene controllers like the GE 45631 or [Enerwave ZWN-SC7] (http://www.thesmartesthouse.com/products/z-wave-7-button-scene-controller-zwn-sc-7-w) seem like they should work, but are there others?

  • (+) A controller switch would allow programmatic control of multiple connected lights and/or scene toggling.
  • (-) Not widely available, and not on list of officially supported devices

B) Do connected switches work without a load? If they do then any connected switch could provide the toggling command signal to SmartThings.

  • (+) Switches are widely available and prices have come down significantly
  • (-) Lights are likely to be slow to respond because of indirect control via app.

###Replace all switches in circuit with switches that do not require a neural.
Lutron Caseta switches do not appear to need a neutral wire, and they have small battery-powered remotes that can be mounted in place of a standard switch. Although Wink compatible, there is no clear indication if the current version is SmartThings compatible with use of the Zigbee standard, or if a Caseta hub and IFTTT are necessary to make Caseta and SmartThings communicate.

  • (+) Wired control of lights would leave least delay to controlling lights after button push.
  • (-) Added cost and potential inter-platform incompatibilities.

Does anyone in the community have experience with one of these solutions?
Is there another solution?

I’m sure @JDRoberts will have some insights.

First, to get the easiest thing out-of-the-way… Lutron uses its own proprietary protocol. It does not use zigbee of any kind. There’s no way to make it communicate directly with a smart things hub.

The home automation hubs that do communicate directly with Lutron devices have added a Lutron radio to their hub. This includes wink and staples connect. Smartthings chose not to do that.

There are multiple ways to get indirect integration, but all but one require that you also have the Lutron smartbridge, as you will actually be communicating with that device, which will then send the radio signals to the individual lutron switches. And the one that doesn’t require the smartbridge requires the staples connect to bridge in a similar way.

  1. simplest. Just use IFTTT integration as both smartthings and Lutron Caseta have a SmartThings service/channel.

Two) use staples connect as a bridge. There’s a thread about this in the forums.

  1. use harmony as a bridge. In this case smart things will talk to harmony, harmony will talk to the Lutron smartbridge, the Lutron smartbridge will talk to the switches.

  2. use a raspberry pi as a bridge.

So any of those can work as far as triggering a Lutron switch from a smartthings Smartapp. I don’t think any of them work in the other direction unless number 4 does.

1 Like

Just to clarify, if you have the line (from breaker) and load (to light) in the same switch box, you wire the master there. After that you only need two lines between the master and aux switches. Those two lines are the neutral and traveler. (GE - Zooz - Homeseer - Enerwave)

If you don’t have that, then you can look at using powered or battery operated Z-Wave add on switches that don’t need a traveler. (Linear - Cooper)

1 Like

Now to discuss auxiliary switches.

(I’m too tired to go into the technical details, but let’s not talk about “scene controllers.” That has a very specific technical meaning within Z wave, and it’s not what you need in a SmartThings environment for what you’re describing. So just don’t worry about those at all. You just need an auxiliary switch.)

OK, there are three ways by which an auxiliary can communicate to the master.

1) physical traveler wire. This is how GE and a few other models do it.

In this case, the auxiliary will be invisible to the smart things hub. It typically, as in the case of GE, doesn’t even have a radio. It normally needs to be on the same neutral as the master.

Two) wirelessly from the auxiliary to the master without telling the hub what happened. This is how the Leviton Vizia plus series is designed to work. It’s also how the Coopers are designed to work if you use direct association with them. These can be Mains powered auxiliaries or battery powered, but in any case they are not load control switches. The ones that are mains powered do need to have power and are typically designed to use a neutral to power their radios. They will show up on your things list. Note that these will need to be within one hop of each other, typically within the same room. And they both need to be Z wave switches that can use association.

( this is where the Z wave “scene controllers” would go but we don’t want to use those with SmartThings because although they can control another Z wave device in the same room, they will not tell SmartThings about any button presses and so you’re really limited in what you can use them for as compared to just a regular zwave auxiliary switch.)

Three) wirelessly from the auxiliary to the hub and then from the hub to the master. Or to any other device. This is commonly how a wall switch controls a smart bulb even if they are of different protocols.

If you go with this option you can add as many devices as you want and you can mix-and-match them however you want because since they are not loadbearing it doesn’t matter what circuits the mains powered ones are on. Each one is just seen as an individual device to SmartThings.

The Linear/GoControl zwave auxiliary switch, the WT00Z model, is popular for this purpose if you don’t need a battery operated one. It looks just like a regular switch except it does not control the load. You don’t have to have a master switch to go with it because it will pair with smartthings as a Z wave switch.

If you want a battery-operated one, the cooper aspire 9500 is popular as it looks the most like a regular wall switch. But a lot of people prefer to go with the button types like the remotec.

You’ll find both of these and more battery operated devices in the buttons FAQ:


In this instance the line and load for the switched circuit are in different switch boxes.

Hopefully @Navat604 or one of the other electrical experts in the community can say more about the wiring pattern. :sunglasses:

I think the WT00Z is probably the easiest way to go.

I ordered a Leviton smart dimmer and returned it because I didn’t like the design. I knew if I installed it other people would get confused and keep hitting the top to turn on the lights when only the bottom switch works as a toggle. It’s not an intuitive user experience compared to all other switches that people encounter.

Thanks for the help. Hopefully this thread provides a more concise answer for others encountering this problem as they teach their old home new tricks.

1 Like

I can’t see how a 4 ways can operate with just 2 wires from each other switch. You won’t be able to turn on the light with one of the switch at certain position. 4 ways means two 3 ways switches and one 4 ways switch. The 3 ways switch has 3 wires connecting to the 3 terminals and the 4 ways has 4 wires to it. Are there wires missing to the switches terminals?
Usually the missing neutral is because it’s at the light fixture but doesn’t sound like you case so I would double check the wiring again.

1 Like

The middle switch box containing the 4-way switch contained 2 x 14-2 wires: 1 from the switch box containing the line voltage, and 1 from the switch box connected to the load (2 lights). The switch box going to the load contained additional switches with a different line from the breaker box run into the switch box containing the last switch. This separate supply to the last switch box contained a neutral that I used for the auxiliary smart switch.

I’m not certain if the original circuit contained the neutral only in the light or was tied to the neutral of the other circuit in the last switch box. All of the white neutrals, other than the 1 from the 4-way switch, were tied together in the last switch box.

I don’t think this would be considered correct with modern electrical code, but I’m not a licensed electrician.

1 Like

Follow-up question: What’s the best device handler and app configuration to use with a wireless auxiliary switch like the WT00Z?

Using the on/off transition of the auxiliary switch to turn the wired circuit on/off doesn’t work without additional apps because the wireless switch can remain “on” when the physical smart switch is turned off. Then the aux. switch doesn’t turn on the lights without turning it off and back on.

Adding a second smart app to toggle the aux. switch with the pressing of the main switch should work as long as things aren’t too delayed, but is there a better/more elegant solution?

You can set it up so that the two switches follow each other. So if you turn on the auxiliary, A message is sent to the master to turn it on. If you turn off the master, a message is sent to the auxiliary to turn it off. It won’t loop in most smart apps because a message to be turned off will not be sent if smart things already has the device with the status of off.

You can do this with many different smart apps and options, I think even the official smart lighting feature will work for this, but you would need to test it to be sure.

The official Smart Lighting feature only allows 1 switch to be selected, but it can toggle multiple lights.

For a wireless 3+ way switch that works through the hub there needs to be multiple switches controlling 1 light (the physically wired switch).

Yes, you have to set up a separate automation for each driver situation. So one smart lighting rule for each auxiliary.

I think I have similar wiring. One box has neutral, one box does not have neutral but has a traveler wire.

I use the traveler wire to send the neutral from one switch box to the other switch box.

The aux linear switch can be set to wirelessly directly control any other switch without the hub or any other intermediate device.

I have linear aux switches controlling other linear switches and GE branded switches.

The aux and main switch do not and do not need to be in sync.

So if I turn on the light from the aux, the aux switch turns on the main switch and the lights go on.

If I operate the main switch, the lights go on or off, the aux is not aware of this, but who cares?

I use an aeon minimote to create the association between the aux switch and load bearing switch that it will control.

The control from the aux switch is instant.

I have 2 sets which are dimmers for LEDs and on set which is on/off, no dimming because in the garage it is old school fluorescents and dimmers would not work.

Whether the aux is being used as a dimmer or a switch I use the same model of linear aux.

To answer the question, even when aux and main are out of sync, it does not matter. Suppose the lights are off, but the aux is on. Clicking the aux on instantly turns the lights on without toggling, even if the aux was already in the on state.

If you are doing the wiring yourself; I would recommend the linear brand aux but not to buy the matching linear load bearing switch; instead buy the GE switch.

The linear brand switches use pigtails which I do not like. I like how the GE switches are wired.

I didn’t do a direct pairing of the Aux switch with the GE wired switch (I totally agree with you about the GE vs other brand connection styles). In my setup both switches are paired with the ST Hub, and then 2 software triggers cause the lights to go on/off and turn the aux switch on/off. When the setup is all based on software triggers, there is no on/off transition to a switch that is already in that state.

Are you able to pair the Linear Aux switches with both the wired switch and the SmartThings hub, or do you pair it with the switch instead of the ST hub?

I have an Aeon minimote, but I hardly use it on my home network. Did you need to include the minimote with the ST hub and then make the association between the GE (wired) and Linear Aux switches?


Yes, yes and yes.

So all the devices are paired with smartthings, the GE light switch, linear Aux switch and the minimote.

Smartthings is the master controller.

Then you press some buttons on the minimote, the GE light switch and the linear aux switch, which tells the aux to directly control the GE switch. This is called direct association.

The direct association will stay as long as the GE switch and linear Aux are paired to the smartthings hub.

Hi @etbrown, @professordave,

I’m new to smartthings and home automation. I think I have the same situation described in this thread. I want to make sure I am understanding etbrown and professordave correctly. The Linear brand aux switch does require a neutral wire but doesn’t require a traveler wire as it pairs directly to the smartthings hub. So you repurpose the traveler wire as a neutral wire to connect it to a neutral bundle in one of the other switch boxes?

This works well with the other switches being the GE switches?

Are there no other options that do not require some kind of Neutral wire connection? No swtiches that can simply draw power from the line/load wires or are battery powered? I was hoping I could find something that is essentially just a z wave remote, maybe not even have to tie it into the wiring but can just put it in the wall where the previous switch was.

Thanks for your help!

This is the exact same setup that I have. My house was built in 2001 so I presume this 4-way setup is to code. There must be a common neutral it just doesn’t run thru this middle switch box. I think I’m going to have to fish a wire to it to provide a neutral. If the line and load wires were in the same box I believe you could wire the original travelers as the low voltage traveler and the common neutral.