LZW31 not working in 3-way application, please help

Hello, I purchased several black dimmers from Inovelli and they all work fine in single pole.
But no luck using as 3-way. It’s a modern home with neutral wire and directions say I can keep the 2nd dumb switch which is at the light, and place the LZW31 in the box which has the Line (hot) wire. Wiring is simple and matches their attached schematic exactly. I followed the insert that has programming steps to tell the dimmer it’s used as 3-way. I also confirmed the Line wire always energized and other switch connect to fixture. I also tried with incandescent instead of LED so I get good wattage like 4 x 60W bulbs.

It connects perfectly to smartthings and dims very well. I can also hear the relay click when turning it on or off. My problem is the dumb switch must be kept flipped in one position or else it’s not possible to turn on the light. It’s as if one traveler wire never gets energized from the LZW31. I verified good connection for neutral, Line, and 2 runners. I also swapped the LZW31 with another and had same issue. I don’t think 2 can be bad and it could be a programming step I may have missed other than what I highlighted in the attached wiring insert. If I have to get a GE or Homeseer for the 2nd switch that is fine, but I feel something is wrong and one traveler never gets energized. My 2nd switch is a new 3-way basic switch, no dimmer, and and I had the same in 1st one before I installed LZW31 and everything worked fine.

I attached photo of the basic Leviton 3-way dumb switch at the box which connects the common terminal to the light fixture, and other 2 terminals are travelers to the new LZW31. This switch must be kept in one position or else cannot turn on the light.

Which hub?

I’m using smartthings hub which works fine and has full control of the dimmer.
But I’m just trying to see it work manually and not require the other switch to be in just one position.
It is always energized and I see the colored LED always.

Ok, thanks.

1 - Did you install the Device Handler? Which one? Might be easer to post a screenshot of the first five lines.

2 - Go into the IDE and open the page for the dimmer. Grab a screenshot of the Current States and Preferences section, please.

Take a look at the instructions below. Inovelli switches require the installation of computer code known as Device Handlers (DH) via the IDE. The IDE is located on the web at https://account.smartthings.com/ .

There are parameters that need to be set to get the switch to work properly in a 3-way environment. I think you’re going to need the DH installed to accomplish that.

Ok done – here is the screen shot of current states & preferences.

So now you have to go into the switch’s settings in the app and set parameters 21 and 22, which are the AC Power Type and Switch Type. It does not look as if you have done that because your settings are empty. So you want neutral and 3-way toggle (called Multi-switch (Dumb Switch) in the documentation).

Ok I have both parameters set to 1 as shown here, but still no luck. I also found that turning on the light using the dumb switch makes it turn on briefly, but then it turns off again very fast by itself. Then I have to turn it back on using the smart dimmer and it’s fine, as long as dumb switch is kept in one position.

What is your load i.e. what bulb(s) are you powering?

My load is a 4-light bath fixture and I have used 60W incandescent (240W total) but now using LED 7W each (28W total).

Try setting the max brightness to 80%.

Hi Brian, thanks for everything even though it still doesn’t work. I got email from Inovelli support saying I was supposed to add the handler before installing the switch, so now I just need to remove it and then put it back and pair it. But I wonder why I can’t just pull the air gap or cut off power at the breaker vs. removing all 4 wires (or just Line wire).

And even if I added the handler first, I thought you need to find the device first in the ST web app before adding that firmware. But if device not installed first, I would not be able to select it when adding the handler firmware.


You don’t need to uninstall the switch. They mean before inclusion. You could try exclude, factory restart, and include.

Sorry for the confusion @ddavid544 - as @stu1811 mentioned, you don’t need to completely uninstall the switch.

In fact, you can install the device handler after you install the switch and pair it to SmartThings (it’s recommended to do it before, but it’s not a big deal).

For LZW31 - here are the directions to install the device handler: https://support.inovelli.com/portal/en/kb/articles/switches-dimmer-black-series-gen-2-lzw31-smartthings-device-handler-installation

This section will show you how to apply that code after you’ve already paired your switch.

From there, you can go into your app, select your device and then click on, “Settings”, scroll down and select, “AC Power Type” and select, “Neutral”.

Then scroll to, “Switch Type” and select, “3-Way Toggle”.

Hopefully that will work.

Hmm, how is the IDE showing parameters 21 and 22 if it’s NOT using the DH? Thinking out loud.

@ddavid544 Report back after you try the above.

Yeah I was wondering the same thing. The weird thing is it says, “enum” so I’m also not sure if it was properly included (not OP’s fault, just sometimes it happens).

Hello guys:

Those were the same directions I followed yesterday and I assigned “Inovelli Dimmer LZW31” for type from the dropdown menu and updated. Then I saw lots of parameters in my ST phone app as expected.

Attached are my latest settings after I changed high level to 80%, low level to 20%, and parameters 21,22 are both “1”. The phone app does not have parameter numbers like shown here, only descriptions. Would be nice if it numbered them.

*** Also: Instructions you sent only mention the RED series dimmer and mine is black series LZW31.

I also tried swapping one of the LED’s by incandescent 60W bulb, but same issue. Can only turn on light when dumb switch (by the load and it is not a dimmer) is set to one position, and can control it using LZW31 with no issues, physically or thru ST

Ok thanks for the screenshot, super helpful!

Question for you: when you flip the dumb switch, does the LED bar turn completely off (ie: not dim - but completely off) or is it dim blue?

Hi Eric, I checked that and the LED bar on LZW31 remains on when dumb switch is flipped, but got dimmer.

It seems to me that the LZW31 is not passing the hot “Line” wire to the other traveler wire when the LZW31 is turned off, just like a dumb 3-way switch is supposed to do. I can pull it out of the wall and use my voltage finder to confirm that neither traveler is hot when LZW31 is turned off. That would explain why the dumb switch only works in one position.
(I know you cannot advise going near a live circuit)

** Also, both original dumb switches are new Leviton 3-way and worked fine before swapping one. However, they are the lighted types where the paddle lights up when it’s off, so that’s my dumb switch as shown in image attached. Does it matter that my dumb switch is illuminated when off?

And I also bought more LZW31 black dimmers so I can swap it if you think my LZW31 defective.