Linear 3way light setup not working once WT00Z is installed

What I have: Linear WS15Z, Linear WT00Z, Aeon Minimote, SmartThings hub

What I’ve done: I installed a Linear WS15Z on/off switch on one end. With the regular paddle on the other end, the light works fine as long as the paddle is in the “on” position

I pulled out the paddle and installed a Linear WT00Z 3-way wall switch on the other end. None of the lights in the hallway will turn on now.

Both ends had 1 red, 2 black (one with 120V and one with 0V), some gray (neutral) bundled together, and one pure copper wire (ground).

On both ends I connected the Linear’s green wire to the pure copper, Linear’s white wire to gray, and capped the red wire.

On the end with the WS15Z, I have the Linear’s blue wire going to the black wire with 0V, and the Linear’s black wire going to the 120V black wire.

On the end with the WT00Z, I have the Linear’s black wire going to the black wire with 120V. I capped the other black wire with 0V.

I used the Aeon Minimote and associated them together.

With the current setup, the blue light on the bottom of the WS15Z turns off when turning the switch on, and it turns on when I turn the switch off. The WT00Z’s light does not come on. I was told this is expected, so this is why I assumed I had the configuration correct.

I even read into the manual and read that JUST the neutral wire going from either end of the hallway should be hooked up to the Linear switches. We tried every single combination and could not get that to work either.

Do you know of anything else that could be going on here? I’m totally baffled.

I even swapped out one WT00Z thinking maybe I had a bad one… Still the same results.

This is a brand new house in the USA, so I’m positive it’s built to code and with all of the wiring standards.

Could it be that I have the switches in the wrong areas? Could it be possible that I need to switch the physical locations that I have the WT00Z and WS15Z? I thought it didn’t matter which was in which spot, but… could it?

I think the reason why it didn’t work is because the way the old wiring could be something similar to this.

also the Wt00z needs only line and neutral so you also might need to re-config the wire ends at the 2 boxes.

Are you able to point me in the right direction about how to reconfigure the wire ends at the boxes?

Sure. The box with the line hot is where the WS15Z should be. We will call this box 1. You mentioned about zero volt so I assume you have a meter or non contact sensor in order to check this. Find out the line hot. Connect black line hot with the red wire. Also connect a pigtail to this bundle as well. We will use this pigtail wire and connect it to line hot on the ws15z.
Neutral should be easy so I will skip that. Now the other black wire will be your load. Connect that to load on the ws15z.

Box 2. The red wire will be your line hot. You can connect that to line hot on your wtooz. Neutral to neutral. Connect you two black together. That’s the load wire going back to your ws15z.

The trick here is to find you line hot. The easiest is to disconnect all your wires and search for the one with 120v.

So, each of the two boxes has 1 wire with 120V, and 1 wire with 0V (both black, for what it’s worth). Does that change what you’re saying?

That’s with all the wires disconnect from each other?
Edit: some electrician take short cut and run line hot to both boxes. If that’s the case then all you need to do is find the load.

Oh, perhaps not. There was a switch on the other end when we tested them… Do I need to unhook both switches to test the wires?

And how do I locate the load?

You don’t have to remove the other switch. But look for the 2 black wires with 120v. When that switch get flip to the opposite position. One of the black wire should have 0v and the red will get 120v. The black that never looses power is your line hot.
Look like the hot line is at the box with the switch still attached.

Sounded like the load is the black wire with no voltage at the box with no switch.

I would remove the switch and look for the line hot. You don’t want to burn down your new house by guessing.