I am trying to replace a single switch connected to a single light bulb with a Z Wave enabled switch, model ZW4001Z; a link to the manual for the switch is at the bottom. There is a wiring diagram on the bottom of page 5 of the manual showing how you are supposed to wire the switch, the diagram uses 3 wires and a ground; the problem is that I only have 2 wires and a ground. How am I supposed to hook up the switch? My wiring looks like this:

My wiring

Switch Manual

  • Is this picture (with the "coded black" wires) what your current setup looks like? Do you have a black wire and a "marked" wire (either coded black, or red or anything other than white) in your switch box? Or do you just have a black, white, and ground wire? – auujay Feb 17 '12 at 21:25
  • @auujay - I have a black, a white and a ground in my box. – Peter Feb 17 '12 at 21:31
  • Can you look at the wires in the light fixture? I suspect your setup is like the picture (but they did not mark the white wire as actually being hot). You need to look in the fixture to see which wire is your "line" (the "coded black" in your diagram) and which is the "load" (the black wire in your diagram). – auujay Feb 17 '12 at 21:37
  • @auujay - I can look in my light fixture and find out, that shouldn't be an issue. You don't think I'll have any issues wiring up the switch with only the two wires despite what the wiring diagram looks like? – Peter Feb 17 '12 at 21:42

If the picture included with your question is what your current setup looks like, you don't have the neutral (white) wire that the installation instructions are expecting.

  • Wire your new switch so that your real black wire (the hot to your light) is connected to the "load" terminal of the switch.
  • Connect your "coded black" wire to the line/hot terminal of your switch.
  • You don't have a neutral wire so leave that terminal empty.
  • Per the instructions: "When used by itself for 2-way control, please make sure that the screw terminal for the traveler wire is insulated (Do Not Remove the tape over the terminal if you are not using the traveler connection)."

EDIT - The more I think about it, you may need to have a neutral wire so you can get the "wireless" and any other "smarts" that are in the switch itself. The diagram above will work fine for a normal switch but you may have trouble with you fancy new one.

  • I'll give it a shot and let you know, thanks. – Peter Feb 17 '12 at 21:47
  • 1
    Your edit is correct. These "smart" switches require positive and neutral to power themselves. – Kellenjb Feb 17 '12 at 22:26
  • What I'm hearing is that without a neutral wire in the box I can't use this switch... Which totally stinks. – Peter Feb 17 '12 at 23:10

Your switch requires a dedicated neutral so that the switches internal electronics can operate independently of the fixture it is connected to.

Your configuration is such that the line (source of power) comes into the ceiling box first instead of where the switch is located.

In order for this to work with the line still coming into the ceiling, there would have to be a third conductor; when the switch was installed, it needed to use 14/3 instead of 14/2 (usually you see this for a 3-way switch).

Your options to fix this is to either run a new 14/3 cable between the switch and fixture, or change the configuration of your circuit so that a line comes into the switch. The complexity of this depends on the distance and cable route between the two.


Oddly, the dimmer switch version does not have a terminal for a neutral/return. There is only Line, Load, & Ground. So depending on what your load is you could install a dimmer switch version.

Note that I'm using GE/Jasco switches.

I have confirmed that the regular 2-way switch will not work without the Return being connected. I don't know why the dimmer switch doesn't need a Return.

  • 3
    Often, one would get a smart switch that needs a neutral because you can't pass low levels of current through that fixture (e.g. CFL bulbs will flicker). Any fixture that can be dimmed can be run at levels that aren't visible to power the switch. – BMitch Dec 16 '12 at 2:56

As mentioned elsewhere, most of the smart switches require a neutral connection so that they can take a little current in order to operate the internal electronics.

Theoretically, it would be possible run neutral wires if you have them close by (from the breaker or a different socket/switch) but that's not going to meet code.

Good news is that there are some switches available that don't need a neutral - the only downside is you have to use incandescent bulbs. This is because they need to draw a little current (which will go through the bulb) in order to operate the switch.

Here are some links (look for requires neutral = no): Dimming Switches and On/off Switches

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