Zooz Zen26 3 Way Switch Wiring

I’m trying to get my backyard patio light switch hooked up to my Zen26 switch but there appears to be a curve ball because both of my switches have black wires that go to a bundle. I’ve contacted Zooz support who helped me install all my other switches but they’re not sure how to wire it either.

See attached photos. The triple box is located in the house and the arrow points to the black bundle. The double box is located in an external garage where also the arrow points to the black bundle. Any assistance would be great and would save me $150. :slight_smile:

You need to identify which of the wires connected to a black, common, terminal on one of the switches is line from the breaker.

Do you have a non-contact tester? It’s the safest way to check for power on your wires.

Get a tester, leave the switches hanging out, and turn power on at the breaker.

Then hold the tester near the black terminal on the switch and carefully flip the switch. On one of your switches, the power will remain on at that terminal regardless of how the switches are set. That’s where you’ll want to put the ZEN26 switch.

From looking at the pictures, I’d bet it will be the three-gang box. The bundle of black wires in that box are most likely the line being distributed to each switch. It looks a lot like a couple of 3-gang boxes where I’ve done Zooz switches. You’re going to have fun squeezing a ZEN26 in there.

I can’t really see what’s going on in the 2-gang box. Is only one light being switched by each switch?

Find your line wire by testing. Then post back.

Tagging @ritchierich for wiring expertise

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This can be normal and depends on which box your load to fixture is. It’s really hard to follow the wires in those pictures given paint all over the wires. Based on my quick look the second picture, one with paint all over wires I believe has your line to breaker. You can confirm this by following wires from the other switch and see if one of them also goes into this bundle. The fact that the black screw (common terminal) on that 3way goes into that large bundle of wires is also a clue. Please let me know.

Now in this same box… follow the other 2 wires hooked up to your left switch, the one you want to replace. That’s a 14-3 Romex and 2 of the wires are hooked up to the switch, what is the other wire hooked up to?

In the other box, first picture:
How many wires are in that bundle?
Do any of those wires connect to the other switch in that box?
How many light fixtures do you have on your patio? That is how many lights turn on with this switch?
I am thinking this is your load but we need to figure out which wires are connected to this.

There are 2 fixtures in the patio. One fixture is on the garage and the other is on the house.

I made a video of the boxes for Zooz support awhile back. Hopefully this can help. :slight_smile:

Reinforces my thought that the 3-gang box has your line from the breaker.

My kind of uneducated guess on the bundled black wires in the 2-gang box is that the two lights it’s controlling are separately wired to the box. So the bundle is:

  • Wire from the switch
  • One wire from each of the two lights

Definitely helps but still have a few final questions:

  1. In double gang box follow the black and white wires that are NOT hooked up to the black common screw. Is that a 14-2 Romex (black, white, ground)? What color is the wire jacket? White?
  2. in triple gang, follow the black and white wires that are NOT hooked up to the black common screw. Is that a 14-2 Romex (black, white, ground)? What color is the wire jacket? Trying to confirm it matches same color as other switch.

I believe you have line in triple given that larger wire bundle has a wire hooked up to both switches. Then load in double gang given you have two fixtures operating off that switch. The gray jacket wire is outdoor rated wire and in video you mention one of the wires in that bundle has a gray jacket.

This would mean you have to use this wiring diagram since you only have a 14-2 (black and white and ground) going between switches. You also appear to have neutral in both locations. Notice red X’s on wires you don’t have or need given neutral in both boxes.

Some more images. Hopefully these will be able to help.

Different color jackets :disappointed_relieved:. Please tell me more about location of these switch boxes and the fixtures. You mentioned above external garage is this attached to the house? Was it an addition to original house? Where are the light fixtures in relation to these switches?

Thinking now you have light between switches.

How can you tell with all the paint overspray? That leftmost Romex looks completely covered in paint to me.

The switches control the 2 lights in the attached (one on the house and the other attached to the garage). The triple box is right next to the house door. The double box is next to the garage door. These are how the houses are built in my neighborhood.

If you zoom in on latest picture he posted you will see it’s the outdoor gray Rome’s that has each wire covered while the screenshot from the video shows a white jacket, non outdoor, Romex.

Ok seeing this picture I believe the power goes from the triple to the light right outside that door, then gray outdoor Romex runs from that light to the other box in Garage and then up to that light. Only way to confirm is to pull down the light fixture on the house.

Another idea is to use a multimeter… while breaker is off, remove the wires from the triple gang switch (ones on gold screws and not going to the bundle) and have someone hold wires to a 9V battery. Then using a multimeter touch the wires hooked up to the other switch gold screws (not the one going to wire bundle) and see if you read 9VDC or -9VDC. I’d then switch the wires on 9V to double check the voltage reverses on the switch. If this does indeed work then my assumption is correct and you can follow the Zooz wiring diagram.

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I think the light fixture route would be easier. What would I need to verify when removing the light fixture on the house?

Really need to see the wiring in the box. You have no gray outdoor Romex in the triple gang box yet you do in the garage switch box so they are coming from somewhere. I suspect they are coming from the fixture.

When I zoom in on the latest picture and look at the leftmost Romex in the 3-gang box, it looks bumpy, like it’s completely covered in wall texture overspray.

But you are probably right, you’re way better at this stuff than me.

That said, don’t all the Zooz ZEN26 and ZEN27 3-way wiring diagrams boil down to: find the box with line and put the smart switch there?

True I was just trying to determine if there are wire changes (broken load wire to light) like in the below diagram because it will matter where the smart switch goes with this situation.

@ainokea did Zooz support have you try the switch at all? I know for a fact you have line power with that larger black wire bundle in your triple gang. The white bundle is also neutral. So if it were me I would just try it and leave the garage 2 gang switch alone.

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Nope, they didn’t have me wire anything. I guess because each switch was wired to a black bundle. I can take another video again. Let me know specifically what kind of info you need. :slight_smile:

Nothing sir. Wire it up! See pictures above

Ok, any chance you can take a look at my wiring to make sure it looks correct? The black is from Zooz support. The red comments and arrows are from me. Not sure if the load and traveler is correct. Also, the neutral I plan on getting from the ZEN26 that I wired from the “K” switch since the bundle is pretty thick. Do I find the white wire in the Romex (it say bundle in my pic) where the load and traveler are coming from and directly hook that to the “BY” ZEN26?