Any additional insight you wish to add?
Such as which wiring diagrams this could work in, etc.?
I’ve seen there are like 9 diff ways to wire 3-way switches.
It would be a great service to the community if we could identify those types and give some basic insight into how to implement it.
I would LOVE to make these work with my 3-way switches. It’s the only things left in my house that needs “z-wave-ified”.
Basically, if you have line, load and neutral in the same gangbox. Then you can get all the relay module to work by using the common wires of both switches as your switch.
Do you know what’s your current wiring look like? It’s easier to figure it out this way instead of me spending hours coming up with all possible ways. Maybe one day I will do that but a little busy at the moment with family and projects.
Here is a reference site for 3 ways.
I have done my best to determine that my setup is looking the most like this:
When either switch turns the light off, there is no constant hot in the fixture or anything and there are only one white and one black coming out of the fixture in the ceiling.
Most if not all of my switch boxes have some form of neutral bundle / hot bundle in them so powering the modules houldn’t be an issue.
Any recommendations for me? if possible, with the Monoprice Z-Wave In-Wall On/Off Module which I have a bunch of but have none of the aeon labs ones right now.
http://www.monoprice.com/product?p_id=11989
This one apparently is capable of being controlled with 2 switches as per the instructions.
Any help is obviously much appreciated. Thanks for responding!
This second wiring I can definitely be able to help.
Remove the load wire from the light switch on the left. And connect that wire to the red wire on you Monoprice module.
Connect the green wire of your Monoprice module to the empty screw terminal (common and usually black color) of the switch previously occupied by the load wire.
Connect black and blue wires of the Monoprice module to the black line hot bundle.
Connect white wire on your Monoprice module to your neutral bundle.
The first and second drawings are not the same. The load wiring bundle goes to different box so relay module won’t work. Z-wave Wall switch and add-on is the only way I know off for the first picture.
To check for line and load. Put your meter negative to neutral and positive to the common screw terminal of the switch. With constant 120v regardless of switches position. That’s your line hot.
The common screw terminal of the switch with voltage changed by flipping switches is your load.
Ahh, oh well… thanks for trying. The more I think about it, the 2nd diagram doesn’t really align with my recollection of the wiring in any of the switches.
I’d venture to say the 1st diagram is the most popular choice for my house… is it generally the most common 3-way setup?
I’ll check it again when I get home but I’m not optimistic… this has been a real disappointment to my money saving venture 
I would say yes due to the number of wiring bundles going into a box. So it’s much easier and cleaner to go with the first picture but some people like to cut down cost by going with the second drawing depending on where your line and load bundle as well.
So given that knowledge, would there not be a way to simply re-purpose the wires and make them work?
Only if those modules support push button then yes otherwise you are out of luck.
You’re just making me sad… 
Thanks again for your insight. I think I’ll just gradually start switching over to GE switches I guess… :-/ 
What’s your opinion on the Enerwave solution with swapping one switch out for a 4-way?
Does this look right?
@Navat604, what do you mean by pushbutton? Could this be done through a smartapp?
I’m thinking that one solution would be to use the dual relay from Monoprice, and then you should be able to replace the 3-way switches with 2 normal switches. Then each switch would trigger one of the internal relays, and a smartapp could make that it interprets that and that it functions like a 3-way.
Just a thought.
It seems though, that it would lose its state at some point? One relay in on position, and one in the off position? I mean, I’m guessing this COULD theoretically be accounted for in the smartapp as well but not sure…
I believe he’s talking about a setup like this:
http://www.thesmartesthouse.com/collections/z-wave-kits/products/aeon-labs-micro-switch-dsc27103-and-touch-panel-lighting-kit-black
Actually, what @Snakedog116 proposed is very clever. I just wasn’t sure you wanted to use both relays in the module to control just one light. You actually don’t have to create a smartapps to do this. Smart light has this ability and it’s local processing. Well… except the dual relay device type is custom so no local process but if that’s what you want then it can be done. Here’s how.
Reference to this drawing. Box on left is box #1 and box on right is #2.
Remove both black wires from switch #1. Connect the 2 black wires together and also have an extra pigtail. This is your line hot wire.
Connect the line hot pigtail back to the common screw terminal of switch #1.
Leave the red wire alone.
You can change the 3 ways switch out with a 2 ways or just leave it and it will still work.
Now on your box #2.
Remove all the wires on the switch.
Connect the light load to the red wire of your Monoprice module.
Neutral of Monoprice module to the white neutral bundle.
Connect the blue wire of your Monoprice module to the red wire previously removed on box #2.
Connect the green wire of your Monoprice module to the common screw terminal of the 3 ways switch on box #2.
Connect line hot black wire to one of the screw terminal switch on box #2. Also line hot to black wire of your Monoprice module.
Now. In ST smart light app. You can tell it to turn both relays on or off when any of the switch is on or off. You will need 2 instances.
Edit: just to be clear. With this setup. You will have physical control of the light when no internet with the switch at box #2. Box #1switch is useless when ST is down.
That’s not going to work with your wiring. Load, line and neutral must be in the same box for that drawing and load is what you don’t have at box 1.
If there is a parameter where you can set the relay module to accept momentary switch then you can have both switches wiring in parallel. I thought I read it somewhere but just can’t remember where and which module.
Actually in my particular boxes I do have power from other switches.
But I think the dual relay + smart lights idea is nicer to me since I can leave the switches alone.
