Odd 4-way setup... line and load not in same box

I have a 4-way non-neutral setup that is wired up as follows:

The only caveat is that, best I can tell, all of the wiring is 2-wire. Given that the line and load don’t run into the same box from the fixture, i don’t think I can wire this properly in anything but smart bulb mode, but I’m not entirely sure. So my questions are:

  1. Is it possible to power a conventional load in this setup with a smart dimmer and 2 aux switches;
  2. If not, how to best wire in this setup so all switches are powered and then use smart bulbs in the fixture and the switches in smart bulb mode for control.

Appreciate everyone’s help.

Nothing odd there. That is a typical 4-way non-neutral setup.

The way it works is that power originates to the light box. The rightmost switch box is fed the constant hot over the white of the 2-wire between the light box and that first switch. That hot is then sent to the LAST (leftmost) box using the white conductor on the 3-wires between the switch boxes. The neutral stays at the light (hence the non-neutral).

The hot is then returned switched through the 4-way switch back to the rightmost box. The switched hot is sent back to the light over the black of the 2-wire up to the light.

This definitely takes, and the diagram shows, 3-wires between the switch boxes. But you posted that you think this is being done with 2-wires. That is not what this diagram depicts, so you might want to take another look at what you have.

If you do have what’s in the diagram, this is easy to wire. The primary box that gets the Inovelli is the rightmost box in the drawing you posted. It get’s wired as a non-neutral. The white (hot) on the 2-wire from the light goes to the Line and the black from the 2-wire goes to the load.

The other 2 boxes need Aux switches. From the Inovelli box, you will send the hot and the traveler. Connect the red on the three wire to the traveler terminal and the white to the 2nd hole on the line terminal. Cap off the black of the 3-wire as it isn’t used.

At the Aux boxes, red to the Traveler terminal and white to Neutral terminal. (That white is hot, but that’s what is required in a non-neutral.)

Like this, except this drawing uses the black of the 3-wire and caps the whites. Color doesn’t matter too much. Pick one . . .


(Thanks @stu1811 for resurrecting my drawing in that other post!!!)

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Thanks for the reply, @Bry. I realize that the diagram depicts 3-wire, but that’s not the way my setup is wired. In box 1, which contains the hot, the hot is a single conductor (1-wire, if you will) to the common terminal of the 3-way switch. 2-wire then runs from the travelers in Box 1 to Box 2, which contains a 4-way switch. Another run of 2-wire runs to Box 3 and connects to the travelers of a 3-way switch in Box 3, which then, again, has a single conductor running out to the load. Pictures are attached so you can see what I’m talking about. I’ve never seen it before.

Box 1:

Box 2:

Box 3:


Ok so you basically have the equivalent of a 3-wire on both ends. The only difference is that you have the old fabric-covered “Romex” and instead of using a 3-wire they used two 2-wires and cut the white conductor off at the end. If you look closely at the top right of the Box 3 pic, you can see a tiny bit of the white conductor.

So this will be a non-neutral. Power originates at the light. You’ll have to confirm which box the hot goes to first by testing with the switches disconnected. After you confirm that, you can do a non-neutral installation with two Aux switches.

If you are using a meter to test, go between the single conductor and the box, which hopefully is grounded. If that doesn’t work, you’ll have to use a non-contact tester.

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Ok so for wiring, my hot is in Box 1 (confirmed via non-contact tester). I wire that to line of the 2-1 switch.

For the 2 conductors that go to Box 2, am I wiring them to the load and traveler of the 2-1 switch in box 1? The diagram above shows wiring to Box 2 from the line, but that would leave my load completely open, which doesn’t seem right.

And then the load wire in box 3 goes to the neutral of the Aux switch?

Yeah, I have to think about this a bit. I’ve done it with a 3-way but 4-way may be a bit different.

The Inovelli has to go in the Load box, Box 3. Auxs go into Box 1 and 2.

At Box 1 where the hot is, incoming hot goes to the Neutral. For the other two conductors going to box 2, black to the Neutral terminal on the Aux and white to the traveler. This sends a hot and traveler to Box 2.

At box 2, both blacks to the neutral terminal and both whites to the traveler terminal.

At Box 1 with the Inovelli, the load wire to the load terminal. The black on the 2-wire from Box 2 to the line terminal and the white to the traveler terminal.

In a non-neutral, Auxs need a hot to the neutral terminal. So you are taking the originating hot and sharing it with the other two boxes. You are also connecting the travelers between all three. So this is a non-neutral with the Inovelli in the load box. You’ll need to configure the Inovelli as a 3 way momentary.

Perfect. I’ll give this a whirl whenever I can get my hands on some Aux switches–apparently they just went out of stock.

If by chance this doesn’t work, my backup is just to put all of these switches in smart bulb mode so the circuit is always complete and then bind the bulbs in the fixture to switches. I think this will work as a fail safe.

Thanks so much for your help. I’ll post once I have the equipment to let you know if it works or not.

Not sure that’s going to work, so hopefully you will not need it. Without rewiring, you won’t have a neutral in any of the boxes. Inovelli switches used in the standalone mode for binding need a hot and a neutral to power.

Can you help me wrap my head around this? If I had the same non-neutral setup but only running to a single 2-1 switch, my thought was that I could just wire this like a standard non-neutral, put the switch into smart bulb mode (which would mean the switch and fixture are powered full time), and then bind the switch and smart bulb together for faster response (or just use a hub if not bound). Does that not work?

I assumed that, for example, if you had a low-load LED bulb that would normally have required a bypass, you could fix that by putting the switch in smart bulb mode to supply power full time and just use a cheap smart bulb. This makes the 2-1 switch more of a remote since it’s not load controlling, but would allow “traditional” switch control as well as smart-control through the home assistant, Siri, Alexa, etc.

Really appreciate the help and quick responses.

Yes, either binding or through the hub will work for the Inovelli switch wired as a non-neutral in the SBM.

The part I was saying wouldn’t work was your suggestion of using 3 Inovellis instead of an Inovelli and 2 Aux switches. The 2 Inovellis that would have no load need a hot and a neutral, which you can’t provide because the neutral remains at the light.

I’m pretty sure you won’t have an issue with the Auxs as we discussed. I have personallhy wired a 3-way in the same way, and a 4-way isn’t really any different. It’s just adding another Aux.

Awesome, man. Thank you so much for your help. Being able to walk through this with another human instead of youtube videos is invaluable.

If you want, you could loosen the wire clamps and see if you can pull more wire into the box so you can use the cut-off wire. Problem is it’s probably cut-off in the light box too. Maybe the electrician left a service loop at each box though.

I do hate seeing that done. That’s a stupid move to not leave the extra wire pigtail in the box.

If you do want to do SMB, then just re-wire to get neutral instead of load from the light at the one end on the single wire. That gets you line and neutral for all the 3 devices, or even use an Inovelli at the line end and feed neutral and traveler from the other 2 over to it.