In wall switch and Add On switch (Honeywell Zwave)

I have a very puzzling problem with an Add-On switch installation. For starters, I am not sure which is the main switch and which is the secondary. However, when looking at the switch that is upstairs, closest to the light, I see 1 black (line) 1 dark gray (load) 1 red (traveler) 1 white (neutral) 1 ground.
When looking at the switch down the stairs, I see 1 dark gray, red, white and ground.

After I plugged all the wires into the new in wall switch upstairs, and into the add on switch downstairs, I was only able to turn the light on, and no matter what, cannot turn it off.

The thing that puzzles me the most is that in all youtube videos I see in the add on switch box, there are 2 blacks, just like the main switch box, and these 2 get piggy tailed together. I only have 1 black in my add on switch box.

You might get a better response if posted pictures of the two boxes with the switches extended to show the wires.

Do you have more than one Romex coming into either box? It’s hard to tell from your description, but the first thing to figure out is where the power is coming from. If you don’t have more than one Romex in either box, then power is coming from the light.


Try looking at this Smart Switch setup for 3-way install.

Brand and model of both the master switch and the add on switch? It makes a big difference as different models are wired differently.

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Depending on the age of the wires some blacks look gray. This said the fact you have 2 blacks in this box I would expect more than 1 white. Forget about what is hooked up to the switch for the moment and describe all the wires in the box behind the switch. Clear pictures help too.

This is only the case when the line is in one box and load in another. In your case I suspect your load and line are in your upstairs box. Again clear picture will help.

Also make sure you note and label the wires hooked up to the bronze/black screw on each of your current dumb switches. We will get to that later after your pictures.

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Honeywell Z-Wave switch and add on

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OK, that’s made by the same OEM company (jasco) that makes the GE brand zwave switches, it just comes in a different box. :sunglasses: That’s good, because it means you can use the resources that are already in the forum on the GE switches. In particular, see the wiring FAQ:

At 1.26 minutes you can see how the main switch has 2 black, 1 red, 1 white, 1 ground.

At 12.30 minutes, you can see they have red and white in the add on, and 2 blacks… I only have 1 black.

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This is downstairs. Where I think the add-on goes.

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This is upstairs, where I think the main switch goes.

I am not home now, I’ll send newer pictures with wire labels.

Thanks. I really need to see inside the upstairs box. I see several white wires in the back but need to see what each is hooked up to. I suspect 2 white wires are connected which should be your neutral and then I expect to see a white and black wire together where the black is your load to fixture or power from breaker.

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Here’s a better look upstairs. I tested with voltage meter, put negative on ground, the black wire to left shows 1.2v the one on right nothing. The red nothing, white obviously neutral showing 126v

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Downstairs, again black lead from tester on ground, the other on that dark gray wire, nothing, red nothing, white 126v

Hate to be bearer of bad news but based on number of wires you have power going to the light first and then to this switch. :disappointed_relieved: This means the Jasco/Honeywell will not work because they require a neutral and you don’t have one. With power coming to light first your 3 way is breaking the positive line while leaving neutral only at fixture. View the FAQ mentioned above for micro switch options unless you can run a wire from fixture to this switch.


Will this work? I still see it says it requires a NEUTRAL?

Unfortunately no and most switches require neutrals. Again view the FAQ since it outlines the options you have without pulling wire.

Thank you very much for your help.

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@ritchierich - The upstairs box has both a 2 wire and a three wire Romex. With this configuration, why do you think the power is going to the light first. With the light powered first, I’d expect only a Single Romex in each box.

@Steve_Barak Go to the upstairs box and check for 120V between the wirenutted white and the black from the 2-wire (not the 3-wire with the red conductor) I think the black you want to check is the one pointing toward the floor. Check with the downstairs switch in both positions.

The box is missing a wire, should be 3 total:

  1. 14-2 Romex for line from breaker, which would include neutral
  2. 14-2 Romex for load to fixture, which would also include neutral for fixture
  3. 14-3 Romex for other 3 way switch

Wire 2 could also be in switch box 2, however there isn’t one. Thus power to fixture first.

Edit, the only other setup based in number of wires is light between switches. This will need to be verified by seeing if either white wire has 120v. But @Steve_Barak mentioned one does:

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Hi @Steve_Barak,

In this case you may be able to use this Zooz Z-wave Plus switch as a replacement for the main switch; it does not require an add on second switch.

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