Old wiring and Z-wave switched: No Neutral. Any options?

I started pulling apparent some of my light switches yesterday in the hopes of putting in some GE/Jasco Z-wave switches. I quickly ran into some problems.

First was a simple on/off switch. Of course, the GE/Jasco switch requires a neutral where as the switch I was replacing just cut the hot-line. There is some neutral in the back of the box so I think I can tie into those and make the switch work. I fear though that some of my other switch will not have neutral lines by them that I can tap into.

Next is a dimmer three-way switch. Wiring for these appears to be much different then what I’d typically expect to see three-way. I believe it will be possible to make it work changing one of the traveling wires to a hot-line and using the other for communication back to the other switch. One switch is in the same box as as my simple on/off, so again I think I can use the neutral there. But the other switch has no neutral.

So I’m wondering… do all z-wave light switches require neutral lines at the switch? From what I can tell the Intermatic also require neutral. I don’t know if there are any other brands out there.

And a corollary question… any one ever have the wiring redone in their house? Mine in the original wiring from when the house was built back in the 1940’s. I know lots of places don’t have ground-lines run to them and some of the wiring has been a little… jury-rigged through the ages. I’m debating whether it makes sense to just get it all updated, especially if I want to start putting in more Z-wave stuff. But I have no idea what the cost would be for a project like this.

This issue is for 3 way switches only , right ?
I am thinking a getting a zwave remote and put it on wall in place of aux switch.

Well, yes and no. From what I can tell you NEED a neutral for even the simple on off switch, so YES it will be a problem for people if you don’t have a neutral available in your switch box.

For me specifically, at location A I have a simple on/off for the kitchen, and a 3-way dimmer for the dinning room (All in one box). At location B I have a 3-way for the dinning room. Location A has neutral that I think I can tap into, so the simple on/off and the main 3-way are not a problem for me (I think). But at location B I don’t have a neutral so I don’t think I can put in the aux.

Putting in a completely stand alone z-wave switch/button is a possibility, but there are two potential problems with that for me.

First, this is a dimmer 3-way, so it whatever standalone switch button is there needs to be able to work with the dimmer.

Second, because the wiring is limited here, I suspect that whatever stand alone button/switch I look at getting will have to be battery operated rather than running off the house line. This means it probably WON’T look the same as the other switch, or even like a switch at all. That might cause an issue with my better half who isn’t a techno-geek like me. She’s more concerned about thinks looking decent rather than being able to do cool stuff with it. :slight_smile:

@chrisb: You might find this helpful:


My general observation is that all of the other switches are a lot more expensive than the Jasco switches. The basic problem seems to be that you need some small amount of current running to power the Z-wave. With the standard dimmer this isn’t an issue, though I believe this can cause the related problem that it won’t work with non-incandescent bulbs.

I have confined my switch replacement to dimmers so I don’t have to worry about this, but I have one 3-way dimmer like you’ve encountered. What I’d really like to find is a battery-powered switch to put on one side, which can then operate over Zigbee or Z-wave to control the light that’s controlled by a Jasco dimmer on the other side. I don’t think such a thing exists, though.

Thanks! That’s actually very helpful. Do you know if they have a matrix like that for dimmer switches?

Nevermind… found it:


So, looking at the lists it appears that the Jasco/GE does make a 3way dimmer where the main switch does NOT require a neutral. It can only handle incandescent loads, but that’s fine for what I’m thinking of putting it. What I can’t tell is if the aux switch still requires neutral or not. :frowning:

If I tke out neutral from adjucent switch and use it for AUX 3 way switch , will it work ?

@chrisb: I got hopeful about that when I saw that chart too, but yeah . . . the auxiliary switch required to make the circuit 3-way does indeed require a neutral.

Okay, I found a the manual for the 45612 along with the wiring diagram.


From this you DO need to connect the aux to a neutral. But, I think I can make this work. The Aux will have to go in the box in the Kitchen that has the neutral. The main will go in the dinning room. There are two travel wires right now that run between the two existing switches. I’ll use one to connect the main to the aux box. The other I will use for the hot wire. Regardless of where power is coming in or going out (kitchen or dining room) it should work perfectly.

Just ordered a couple of the 45612s that DON’T require a neutral. I’ll report how they work out for me after I get this installed.

A note to anyone if you didn’t read the whole thread: The 45612 itself does not require a neutral, but the aux device if you’re installing in a three-way setup DOES require a neutral. The 45612 is also only supposed to be used for incandescent lighting, not CFLs or LEDs.

Here’s a possibly stupid question. Could you install two dimmer switches on the circuit in series and then set them up through ST to mirror each other? Which is to say, I come in and hit switch A. It returns both switches to their on state. I walk over and hold down the bottom of switch B, which ramps down both switches until they’re both off.

Would there be too much delay for this to work smoothly? Would there not be enough current running through both switches to operate Z-wave if they were both off?

I don’t think that be possible Gray. For multiple reasons, but foremost being it is in the circuit directly powering the light.

I thought about a similar setup Gray. I thought about by passing switch B entirely from the circuit. Switch A is the only one that is actually connect to the light. Switch B would basically be just a loop with no load on it. Software-wise then you’d just say: Whatever action you see from switch B should be done to switch A.

I think you’d have some delay there, but I don’t know if it would be impossible to overcome.

My biggest worry would be that having no load could me a lot of energy wasted when switch B was on. I suppose you could, again, software-wise, just have B turn off a second or so after every action. I don’t know if that work or not, just spit-balling…

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Well… don’t flame me for this - it’s not per code and really not kosher but i’ve seen it done before and i’ve done it myself once or twice. Your nuetral wires and ground wires all terminate at the same location in your breaker box. Open your breaker box and take a look at the poles. Do you see white nuetral wires and ground copper wires all wrapped on the same pole? If this is the case you “could” simply pigtail your ground wire into the neutral spot AND ground spot on the switch. I did this to one of the switches you mention and it worked fine. I learned this trick from a union electrician.

Thanks for the idea… I might try it sometime if I can. One of my problems is that in some areas they don’t even have ground wires properly installed!

Just got my 45612s in this morning. Hope to have at least one installed this evening to test it out. I’ll report back.

Got one of my 45612’s installed tonight. Works very well with the incandescent lights. I might try putting some LEDs in later and see how it works.

I am facing a similar situation in which there is no neutral wire connected to the old switch. There is a black wire which I assume is the load and a yellow that I think is the line. Is this correct? There is a bunch of white wires connected in and tied off in the back of the box. Are these the neutral wires? Can I just feed one into the neutral on the 45609?


That bundle of white wires are often the neutral wires. But, it may be worth getting an electrician to at least drop in and look. Maybe you could call some local electricians and offer $10-20 for them to not to ANYTHING but come in and help identify one way or the other. Just explain that you can install them yourself - you JUST need help identifying if they are neutrals.

Another option for people without neutrals - is very often your outlets have them and you’ll often find an outlet close to a light switch. You can string a wire from the switch down to the outlet behind the wall… at least that’s how I got mine working. :stuck_out_tongue:

Again however - might be worth the $20 to call someone and see if they will simply help with identification.


Almost certainly yes. If you have access to an electrician handy (like a brother in my case) and can test this a little bit and let you know for sure, but I’d be pretty comfortable saying those bundles of white are neutral.

The line vs. load I’m not as sure on. Yellow is not typically used for line or load that I’m aware of. I think yellow tends to be used for a traveler wire in a 3-way setup. But of course that is by NO means a certainty. There is no hard an fast rules that say you MUST use this color. (And even if there were those rules, heaven knows the gov’t would change it’s mind every other decade and re-write what each color means!)