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

There is nothing strange about this. The ground and neutral are very similar because they are using the same reference point but for different purpose. Neutral is for carrying load current back to your panel and ground is for protection and should not have any current. You are taking a high electrical shock risk for using ground instead of neutral. Ground wire is usually one size smaller than line or neutral. That’s why it’s easier to pull. If you are pulling a ground wire. Why not a neutral as well. It’s not that much more difficult to do and will give you better sleep without thinking about fire or shock.

1 Like

I don’t have ground or nuetral so I have been using bulbs everywhere. I would love to be able to use switches.

I wanted to reply to this relatively quiet thread to share my own experiences and how a buddy of mine who is an electrician helped me out to get this set up. In my situation, I had a neutral at one switch, but not at the second switch (considered the add on switch going forward). The products that I used were the GE Z Wave Toggle Switch and the the GE Add On Switch. I ran into the same problem that spawned this thread, and luckily my friend was able to help me out.

If you look at the original installation for the three way switch, you have the power coming from A and out to the light through C. (see my own reply to see diagram)

Take note that in the Add On switch instructions, this is nearly the exact same thing, except that the connection to the light happens at the second switch box (at the add on switch).

(see my own reply to see diagram)

What he did was to connect the main switch directly to the load (to the light) like the original instructions, then pigtail T1 to the neutral. At the add on switch side, he capped off the load to the light (instead of connecting it to T1), and then connected the jumper for neutral to T1. The rest of the connections remained the same with T2 going as the Traveler.

(sorry about shoddy diagram, I used Paint to stitch together the two manuals and then edit to show what he did)

1 Like

Only allowed me to do one image at a time…here is original instructions for the Z Wave Switch

Here is the original diagram for the add on switch.

@Navat604 or one of the other electrical experts in the community can say more, but almost certainly what your friend did, if he is a licensed electrician, is to bring over the neutral. Not the ground. A ground should never be used to substitute for a neutral. But it is quite common to “fish up” a neutral from another nearby outlet or switchbox and tie it in to the auxiliary switch.

Not sure why your electrician buddy violated code by using the ground for your neutral to the add-on switch when you have enough wires from your primary box to add on box for neutral, traveler and ground which the add-on requires.

1 Like

You’re absolutely right, it was neutral, not ground.i said it right in one spot and wrong in the other. I think the wiring diagram shows it right.

1 Like

Ah it was my mistake. It was not to ground but to neutral.


Hey, that’s why electricians get paid what they do: this stuff is confusing! :wink:

Just wanted to get it clarified for people who read this thread in the future.

Fishing a neutral through from another switch box is what worked for me in almost every instance in my house. There was only one place where I couldn’t find a close by neutral and I ended up using an aeotec in-wall (in the fixture actually) dimmer in that case. If I were to do it again I’d just put a cree smart bulb there instead.

In 3-way switch setups you only have bring the neutral to one of the switch boxes. That’s where your “main” switch goes, and since the add on switch (the jasco ge ones I used anyway) only require 2 wires instead of the 3 used in a standard “dumb” configuration, I was able to send signal to it over one of the existing traveller wires, neutral over another, and abandon the 3rd.

That said, now that this is all done I don’t think I’ve touched an actual switch in weeks.

Can u just fish a 14 gauge wire from another location through the attic and back down to dummie switch? Does it need to have any conduit or shielding? Is it acceptable to just have the wire

If you’re going to fish neutral from another location like an outlet, you will want it to be on the same circuit to be safe (and compliant with electric code). There’s a really good explanation for why they should be on the same circuit here. From a purely functional perspective, a neutral from any circuit could work (especially given the very low currents we’re talking), but just because it might be functional, it doesn’t mean it’s safe. As for your second question, I would imagine that neutral requires shielding as it is carrying a little current and you don’t want it to short on any metal it might come in contact with. For what it’s worth, I’m not an electrician however I do have a degree in electrical engineering.

I have the same issue, I have put in the Luron Caseta switches, Currently not supported by SmartThings but they say it is coming. I added a Raspberry PI to my system and am running the Smart App and it works great.

1 Like

You mention very low currents. I assume that the neutral from the light fixture is taking the heavy load back and the “fished” neutral is only taking the return from the zwave switch powerflow itself. So I am wondering if the risk is textbook only, or if it represents a real safety hazard.

Or you can look at another angle. A faulty z-wave switch could give out high current on this neutral wire so it’s not just a textbook only theory. Just remember. Code is just a bare minimum standard and it’s there for a reason.

Thanks, that helps.

I had the same no neutral issue on a few of my switches. I went with the Lutron Caseta option with Hub and linked to SmartThings and it works great.

Another option is the Fibaro dual relay. It doesn’t require a neutral, but you have to also install the addon relay to use CFL/LED bulbs, so once the prices are compared Lutron Caseta ends out being cheaper and who doesn’t like a new toy :slight_smile:


I did the same…Lutron Caseta. After putting GE Z-Wave (and plus) switches everywhere in the house, I found 3 places they would not work, becasue the common didn’t go to the box. Two had the power to the fixture, then the switch… One Lutron Hub (starter kit) and I was good to go. They work fine. The dimmers were cheaper, than the regular switches, so I went with those. They seemed to work OK on my third floor florescents…most of the time. The upside is I can use a Pico switch on the first floor to control my upstairs hall lights now. The downside was I had to but Pico wall mounts, and color change kits, for ivory, and they are hard to find. (Home Depot special order…free ship to store)

1 Like

Thanks for posting this, it was helpful for the wiring I encountered. The first box in the chain was fed from the circuit box, so a neutral was available. The load to the light was also connected from this first box, but not directly from the first switch. The downstream boxes used the black and red wires of 12-3 Romex as the switched load and traveler, and the white wire as the common return from the last switch. I changed the first box to drive the load to the lights directly like you described, then repurposed the white wire in the 12-3 bundle to slave switches as the neutral. You saved me from returning the switches to the store and shopping for another alternative.