GE Jasco 12723/12724 4 way switch install only working on 2 switches

Is that neutral on the same circuit. If so then yes this should work.

I’m not sure if it is on the same circuit. I think so. I read elsewhere on the net that the neutral is essentially just a path back to the breaker box and that it does not have to be on the same circuit. They emphasized “NOT”. I do not know if that is accurate however.

I have three junction boxes. In box 1 I have two red and two white (plus ground) connected to the 4 way switch. No black on the switch, instead the back are wired nutted together. Also in this box I have two white wires wire-nutted together not attached to anything. In box 2 I have just one romex feed. White, red and black and ground attached to the switch. Using a volt meter I only get 120v between the black screw and ground when the switch is in one position. So I do not believe this is the line. In box 3 I also have just one romex feed. White, red, green and black attached to the switch. Unlike in box 2, in this box 3 I do get 120v between the black screw and ground regardless of the switch position. So clearly this is the Line. So to summarize, box 1 is the 4 way, box 2 and 3 are the 3 ways, with box 3 apparently having the Line and box 2 feeding the load (light). In box 1 there are a total of FIVE romex feeds, which I think two are for a separate 3-way (more on that below) and the other 3 are for the 4 way I’m concerned with here, I think…

In box 1 there are two switches. One switch is related to this 4 way setup. The other is part of a separate 3-way for a different light. I have already installed a GE 12722 into box 1 for that separate 3-way unrelated to this 4 way, and tapped the wire nutted whites in there to feed the 12722 in that box. I then have the add-on 12723 switch in another junction box. So that separate three way with a 12722 and 12723 is installed and working great for that. So I am not trying to get this 4-way for the other light working, which happens to share a same junction box with the Line/Primary switch for it in this same box. I only mention that part here to say that I am successfully using the neutral feed from there for that. I have pigtailed another lead off of that which I plan to use to feed the neutral for this 4-way setup for the other light. I hope I am making sense here…

OK so with that background I’m hoping now that you have the full picture of what I am trying to do. My questions are:

  1. Which box should I set up as my primary for the 12722? In box 3 there is the Line so I kind of think that means I must use box 3 as the primary? I would have the black wire for Line, the white wire in it for Neutral (can this be used even tho its not part of a wire-nutted loop?), and red wire for a traveler, however I would have NO wire set pass along for Load. So I think that means I cannot use box 3 as the primary. Which means I’d have to use box 1 as the primary then. However at box 1 I have no “Line”. Only black wires in there are wire nutted together.

  2. If you or someone can kindly tell me what box needs to be primary, and how to wire it per #1 above that wold be fantastic. Then from there, can you please explain what wiring I would need to do in boxes 2 and 3? It seems that I will somehow need to reuse the wires for different purposes to get this to work, if that’s even possible? I do know that running any additional wires to/from box 3 is not possible, tho if absolutely necessary I could run wires between box 1 and 2, I think.

Thank you!!

EDIT: I meant to also say that the 3 way setup (the one already working GE 12722/12723 system) that shares a box with the 4 way in box 1 are one separate circuits from each other, in case that matters. That said, I am feeding that 3-way with the neutral that seems to be part of the 4-way and that is working. I think the main challenge is that the neutral is in a different box (box 1) than the Line power feed (box 3).

Great. The remaining challenge is that there is no “Line” in the 4 way box where the neutral is. There are two black wires wire-nutted together. Unless I am supposed to break those apart and reroute this somehow? Please see the details here GE Jasco 12723/12724 4 way switch install only working on 2 switches . I am hoping to get enough info to finish this project today. Thank you.

It is very important that you disconnect all the wires from all the switches in this 4 way setup and wire nuts so you can determine which wire is the line from the breaker panel. You can leave the other switches in box 1 alone. You also need to figure out which wire is the load to your fixture. I would bet both are in box 1 based on what you you have provided. From there a post of mine from last year should get you going to get this setup:

Thank you Michael. Once are the wires are disconnected how do I determine which is the Line and which is the load? The Line will be the only one that has 120v between the black I measure and ground? How about which is to the load? There are three lights that make up the group of lights (all on or off) that this 4 way controls. Hopefully this will not require removing those light fixtures as that will be very challenging due to their type and location. Also I was unclear in your subpost where it said to remove the white wire from the bundle of black wires, as I do not have a bundle of black wires with a white.

Here’s some more info that I hope will help you assess the situation. In reviewing this page there appears to be only one possible wiring scenario based on how the 4 way switch itself is set up, and that is this one “Source and light center” as diagrammed below:

I say this because when I look at the 4 way switch in box 1 (the only switch with 4 wires connected) it is the only one that has two red along one side and two white on the other side. The other diagrams either have the white and red across the tops/bottoms (not sides) or involve the black wires attached, which there are none attached on my 4 way switch.

Also here are a few more observations that may help… In box 2 and 3 there is only one Romex with red/white/black/green all attached. No additional wires wire-nutted in these box - just the single Romex. And in box 1 with the 4 way switch there are apparently 4 Romex wires used for this 4 way setup - 2 red and 2 white come out of 2 of these Romex feeds and go to the switch. Then there are two blacks and two whites which are wire-nutted together across various Romex feeds in there.

What I’m hoping to get is an updated “best guess” from you on what approach I should try as an experiment and see if it works (aka most likely to work do this and that). Thank you!

Edit: Just to clarify, box 1 has two sets of 2 black wires wire nutted together and one group of 2 white wires wired nutted together.

Disclaimer here, I am not an electrician by trade and I am only providing advice as a favor via this forum. If you don’t feel comfortable with this you may want to hire an electrician.

Based on what you have provided boxes 2 and 3 only have 1 romex wire coming in right? No other wires in those boxes? If so then your line and load have to be in box 1. The line will be the hot wire that you can measure 120v on using either a ground or neutral. The load is typically a wire with just a white, black, and ground, unless this is a fan where sometimes a wire with red/white/black is used. Again I say typically based on my experience in my own home.

So if you look at all the romex wires hooked up to the 4 way switch, you should have 3 total: 2 with red, white, and black that feed box 2 and 3, and another wire with just white and black. The white and black again should be your load and it may not be hooked directly to the switch, but it could be connected to one of the wires in the red/white/black romex wires. Again this wire will either be hooked up to the switch directly or one of the red/white/black wires.

Once you figure that out, then its really rather easy to setup.

Box 1:

  1. Wire nut the two white wires from the red/white/black romex wires along with a short wire that will go into the neutral of your new switch. This will feed a neutral to your aux switches in box 2 and 3.
  2. Get a short wire and connect this to your neutral bundle in the box and also hook up that to your new switch.
  3. Hook up both red wires to your switch for travelers.
  4. Put a wire nut on both of the black wires on your red/white/black wires since you no longer need those.
  5. Hook up the black load wire to the load
  6. Hook up the black line wire, 120v, to the line

Box 2-3:

  1. Put a wire nut on the black wire as you don’t need those.
  2. Hook up the white to the neutral
  3. Hook up the red to the traveler

I hope this helps. I about to start a project of my own and won’t be able to reply until this evening. Good luck!

Thank you! One point of confusion is that I have four Romex wires involved in this 4 way (plus one additional Romex wire in the same box unrelated to this 4 way, for the other 3 way). Two Romex feeds are red/black/white, and two are white/black. The 4-way setup controls a set of 4 hallway lights that act as a group, either all on or all off, as any switch is flipped. So perhaps one of the black/white Romex goes to one of the lights and the other goes to another of the lights and the light in the middle is wired to each light. I’m just guessing here, but the point is there are 4 Romex feeds in the box not 3. How does this change things?

I made a diagram that shows how these 4 Romex feeds are connected in the box (box 1). They are labeled R1-R4, as in Romex 1, Romex 2 etc. Also shown is the switch with the four terminals that is in this same box, with the top left and top right screws being the black screws. Please ignore the arrows on the lines (couldn’t get the drawing program not to put the arrow heads on them). The junction boxes for the other two switches are not shown. Those are as described in a previous post - just a single Romex with a black wire on the black screw, red wire and white. I suppose we can assume that these are feed from the R1 and R2 in the diagram. And perhaps R3 or R4 represents the Line and the other represents the load? Here’s the diagram:

Sorry to be dense about it, but I wasn’t quite able to follow some of the steps you outlined. Like how the whites in box 1 step one are different than the whites in box 1 step 2. And when you say in step 3 to hook up both red wires to the switch as travelers, since there is only one terminal on the 12722 switch for a traveler, and then something needs to connect to the switch as Load, at least normally?

What would be tremendously helpful and most clear would be if you could kindly explain step by step what to do with the wires from each Romex. For instance “put a wire nut between the whites from R3 and R4 and connect a tail to that and put that into the Neutral on the 12722” like that?

Thank you so much. I feel like we’re getting close and hopefully this post along with your response will do the trick! :blush:

Where is your line (power from breaker) in this setup? Is that a 5th romex?

I am not sure what r3 and r4 are doing in this setup but suspect they are your load to the fixtures. Maybe @Navat604 has an idea.

I’m not sure where the Line is. My guess is that its on R3 or R4. There’s not a 5th Romex, at least not for these (there is a 5th but that’s definitely for the unrelated 3-way for a different light). FWIW box 3 with just a single romex has 120v on the black wire that’s on the black screw regardless of the position of the switch (inferring that its hot, but that’s likely fed from R2 or Rr1, I would think, since you said the Line must be in this box with the 4 way switch since there’s only a single romex in the other boxes (the ones that don’t have the 4 way switch). And to answer your question earlier, no there are no fans involved here.

I would say R4 is your line and R3 is your load. You don’t see this type of wiring very often due to space in the gangbox with so many romex but they do exist. You can confirm by disconnecting the wire connectors and a meter.

Thanks guys! @ritchierich

Assuming R4 is Line and R3 is load, how would I wire up this box? What wires would get wired nutted together and what wires would go where on the 12722 and on the two 12723.

And yes you bring up a great point which was the next challenge on my mind. I have to fit TWO 12722 devices in this box (one as part of a 3 way, separate from this 4 way). I was looking at it earlier today wondering if I will be able to fit all this into this 2 gang box. It measures roughly 3" deep and I think its about 34-35cu. I looked to see if there is an extra deep two gang box but I think this is actually one. What would you recommend if this box isn’t deep enough and I just can’t fit both 12722 devices in the same box?

Thanks again!

@ritchierich Thank you. With @Navat604 saying that R4 is likely line and R3 is likely load - the more I have looked at it, I’m quite certain he is right (it is the only logical explanation). I will test to confirm.

Assuming that is the case, I want to make sure I have this straight. Here is my plan which is what I think is essentially what you already outlined in GE Jasco 12723/12724 4 way switch install only working on 2 switches but that was before you had my wiring diagram. So with this post I hope you confirm that is still your thinking and to get clarity on a few points in your post.

Here is my plan:

  1. In one way or another tie all 4 whites (R1-R4) together and pig tail that into the neutral terminal on the primary.
  2. Connect the black from R4 and put that into the Line terminal on the primary switch.
  3. Connect the black from R3 and put that into the Load terminal on the primary switch.
  4. Tie the red from R1 and R2 together (??) and connect that to the Traveler terminal on the primary switch.
  5. At the add-on switch locations, cap off the black wire, attach white to the Neutral terminal and red to the Traveler.
  6. Of course connect all the grounds as they should be.

Does this make sense? Anything I may want to do different?

Lastly - I don’t see how I am going to get this to all fit in the current 2 gang 3" deep box, because the 12722 is much larger than a regular switch, and to top it off, I will have TWO of them in there (the other 12722 is for a totally different light/circuit). Is there such a thing as a extra extra deep box, something that’s maybe 4" deep? If so can you send a link as I haven’t been able to find one.

Thank you again and Ray for all the great help!

You really need to test to make absolute sure. Disconnect both white and black on both R3 and R4 from any wires they are connected to and verify if one of them has 120V. You can verify if the other wire is the load to your fixture by connecting the white wires together and then hook up the black to a “dumb” single pole switch to see if your lights turn on. Its up to you if you want to test this but at least you know for sure that one is the line and the other is the load.

Each of the screw terminals on the back of the 12723 and 12724 can accept two wires. So you can use that to “tie” the red wires together from R1 and R2:

In regards to a larger gang box, Cantex makes the largest box that I have seen.

Its a new work box, meaning there are nails on top and bottom and flanges on the side, but with a hack saw you can easily cut those off and insert into the hole in your wall and then use a few drywall screws to attach it to a stud on one of the sides - this is assuming your existing box is right next to a stud. Again just use a few drywall screws and go through the plastic on the side of the box and into the stud. If in the middle then your options are limited because the 34cu box you have now is the largest “old work” box I have seen. Grainger has locations throughout the US so hopefully there is one near you.

Make sure you remove the metal tabs on the side of your GE switches. There are 3 on each side and you can use pliers to bend them off. This will give you more room in the front of your box.

Excellent, thank you. So just to confirm, my recap on how to wire this up - assuming the line and load are correctly identified - makes sense and nothing you’d change there right?

Regarding testing for line/load - its easy enough to test for Line so I’ll definitely do that. However I think once the Line is confirmed on R3 or R4, the only possibility of Load would be the other of the two, right? I can do the test for Load but I didn’t exactly follow you on those steps. In that case take a dumb switch and hook up the white wires to the neutral, black wire from R3/R4 to the black screw and hook up ground and then see if throwing the switch turns the light on / off with everything else disconnected?

Thanks for the link to that work box. However that is only 3" deep which is what I have now. I’m looking for something else deeper. I’m first going to try and see if it’ll all fit in there. yes I have already broken the adjacent tags on the two 12722.

This box is 48cu so its definitely bigger. I don’t believe you will find anything larger but trying to get yours to work first is a good idea.

Your steps are fine and very similar to what I have already provided. The key is to locate your hot wire and from there it gets simple. But honestly if you are not comfortable with this hire an electrician and have him/her show you how to to this so you will learn. Forum settings with lots of back and forth questions isn’t always the best solution.

Thanks. You have been tremendously helpful. Yes it seems quite obvious know that I have spent so much time learning about it, especially the old-ball yet “accepted” way my wiring is. Certainly not what I expected to find and not very friendly to just swapping in the 12722/12723. I’ll be trying this soon and will let you know how I make out.

I just wanted to say thank you very much for all your wonderful help. @Navat604 was exactly correct in his best-guess on which wire was what. Everything is installed and working flawlessly. It I couldn’t have done this with your help and I very much appreciate it. This was the last piece of a larger project and glad I was able to finally wrap it up. Thanks again and have a wonderful holiday!

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I made a YouTube video for the power at switch scenario. Sorry to necro-post, but this thread is the first hit on Google for 12724 4-way, so I thought I’d leave it here as a reference.


Bravo on the video. I have read a bunch of things on 4 way switches and just couldn’t get the concept right in terms of how it is supposed to work but yours is very clear!

1 hour and it’s done and works!! Wish I could give you a hundred likes for this video!!! Thank you so much!