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

The micros definitely give you more options, so they’re certainly worth considering.

You might also take a look at the thread on switches for smart bulbs. There are several ways to get around the problem of someone turning them off. For example, there’s a new battery operated zwave smart switch that fits over the top of the existing wall switch. You leave the existing wall switch always on to power the smart bulbs, but you still have an intuitive switch that can be used at the wall.

So lots of choices, it just depends what works best for you. :sunglasses:

One problem. Looks like according to the web information linked, the micro dimmer and micro switch cannot control LED bulbs “with a trailing edge”? Is that accurate and what means it? (Are the standard Cree and Philips bulbs I’m buying at Home Depot going to present a problem?)

"With LED lights.

For the control of LED lights with a trailing edge, Z-Wave dimming products are not suitable."

Well, I just switched ALL of my lights to LED and now one of my LEDs is always on (VERY dim) - THANKS for the explanation!

Watch out for the hue bulbs. The last I heard if they lose power, they don’t come back on in their last state, they come on full white light and Phillips is citing legal reasons for not changing it. So when my kids turn off the lights at night at the switch, the lights are of course now unreachable, and when they do come back to life, they are bright white and on, even if their last state was off.

The good news for me is that most of the three way switches I have to deal with are in multi gang boxes with other traditional light switches so there is a bundle of ground wires in the back I can use. In the one place where I have a three way switch in a single gang box, there is a closet with a light switch right behind it on the same wall. So I’m just gonna move that switch outside the closet and put both switches in a 2 gang box where I will have a ground. Fishing the neutral up from another box, just doesn’t seem safe to me. 10 years from now when you sell your house someone is gonna find that ground wire and have no idea what is going on.

And one other comment to the folks back up in the comments that are dealing with knob and tube, and old cloth wrapped wire. It may still be working, but there are inherent problems with it and you really should look at upgrading your wiring to current standards when you can. And look at it this way, if you upgrade your wiring, you can make sure you have a ground in all of your switch boxes.

Smart bulbs are intended to always have power available (see the user guide), but you can solve the switch issue in many different ways. :sunglasses::level_slider::bulb:

See the following FAQ (this is a clickable link)

My point is the Hue bulbs come back on after a power outage, or after a traditional switch is thrown in a set state that you as the homeowner can’t control. I have a couple of sylvania lights coming in that are supposed to have a user configurable default state so that they don’t come on in a state that you don’t expect. If I had that feature, I wouldn’t mind using a standard switch so much because once the bulb comes back on, it’s easy enough to change it’s state to what I want in just a couple of seconds.
Whoever comes up with an easily implementable solution to the issue of three way switches without neutrals, that supports LED bulbs is gonna have a nice income stream for a while I think.

The problem is that using the standard switch and frequently cutting power to the smart bulbs is likely to shorten the lifespan of the smart bulbs all together. They’re just not designed to be used that way. The simplest solution these days is one of the smart switch covers that fits over the existing switch but doesn’t actually cut power to the bulb. But then you do have to pay for one more device.

Whoever comes up with an easily implementable solution to the issue of three way switches without neutrals, that supports LED bulbs is gonna have a nice income stream for a while I think.

Lutron did it. :wink: And patented it. :bulb: And indeed makes good revenue from it. :chart_with_upwards_trend:

Unfortunately, unlike wink and staples connect, SmartThings doesn’t have an official Lutron integration.

You can get indirect integration because both Lutron and smartthings have an IFTTT channel/service , and it works well for many use cases, but it does add some additional lag which means it doesn’t really work well with Lutron lights triggered by SmartThings motion sensors. But for time based automations or turning things off, it works fine. :sunglasses:

I was under the impression that Lutron’s solution doesn’t work with LED or CFL bulbs.

Nope, works just fine with dumb dimmable LEDs and CFL’s.

You may be thinking of the older GE Zwave switches which didn’t require a neutral. Those only worked with incandescents.

But Lutron is an engineering company and went to work and just a couple of years ago introduced the Caseta line specifically to address the issue of LEDs without neutral wires.

These are the ones that they’ve tested, but most work fine.



Are there any outlets on that line? If so, then (if I understand this right) anything plugged in with a ground will present a potential shock hazard as someone touching it can provide a path to earth. Also, if there is a GFCI earlier in the path, it will probably trip as the switch will look like a voltage leak to the GFCI. At least, I think these are the main worries.

The missing neutral problem has been a big pain for me. Someone ran some of the switches in my house using 3 wire cable, but didn’t bother to connect the neutrals. That’s a easy fix. Just irritating. Sloppy. I have other switch loops run with 2 wire cable. These are hopeless. . . .

I bought some z wave relays that I’m going to install in some of the light fixtures.

That’s what I ran into as well, but mine is a new house. I understand why they didn’t run the neutrals to the switch, it’s just a pain because what we are doing is more advanced than the standard builder wires for today. The best option I found and in my book it’s still not really safe, is to pigtail to an outlet or switch near by. From what I understand the CGFI is typically off the line side so it shouldn’t be a problem. As for the neutral, it shouldn’t be a problem electrically. Note though, I’m saying Neutral meaning the path back to the panel intended to carry current vs the Ground which I am calling the bare wire that is a safety path back to the panel, which is not intended to carry current except in a problem situation.

And that’s interesting. In the circuit box the neutrals and grounds are all tied together. And I have often wondered just what might happen should a ground be used as a neutral… Not that I’m advocating this.

So the reasons this should not be done are well explained here:


Which is old news and correct. But a Z-Wave device is going to require an extremely small amount of current and I wonder just how unsafe it would be.

Totally unsafe to power from the ground instead of the neutral. Definitely not a good idea. :rotating_light: :fire_engine::ambulance:

As far as branching a neutral from a nearby device, that can indeed be done both safely and to code just depending on the exact wiring set up. @Navat604 or one of the other electricians in the community can explain more about that option. :sunglasses:

I thought that exact same thing. There is only about 20 volts going to the “add-on” switch. So I tried it. My lights lit up and everything. Then I tried to turn them off. They wouldn’t turn off. I’m still not sure electrically why that happened. I can’t come up with a reason why that would cause the lights to shine, but connecting through the ground didn’t. But it did. The only thing I can think is that maybe there is some current slipping onto the ground somewhere that was able to find it’s way back through the circuit and power the lights that way. Either way, I finally fished the ground wires from the closet switch directly behind the switch I was working on over to this one, and when I connected to that. everything worked fine. Go Figure.

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.

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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)

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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.