Can I Install Multiple Smart Switches in a 3-Way, 4-Way, etc?

Can I Install Multiple Smart Switches in a 3-Way, 4-Way, etc?

Summary (TLDR)

You sure can, however, there are a few steps you should take to make the experience optimal. This is a great solution for people that want to use an alternative wiring scheme or want to have notifications and scene control at both locations. The main drawback is probably that the "slave" (non-load) switch doesn't show the other switches level, but you can make that less annoying by turning the switch off or to 99% and disabling the relay. That will give the LED bar a consistent look and still allow you to use notifications on it. 

Multi-Smart Switch Limitations

All our smart switches were not designed to be directly wired to one another the same way normal 3-Way setups work. They were, instead, designed to work with either a dumb/existing on/off switch or an auxiliary switch (GE or HomeSeer). 

Below is one example of how you can wire the switches to create this "virtual 3-way". There are a few different methods you could use but this is the key to get it working:

The non-load switch only needs to have line and neutral. This means you can use the traveler wires from a 3-way to get those two things to your non-load switch. Below is one diagram.


Figure 1.1 - How to Wire Two Smart Switches Together

The other limitations are:
  1. Delay: This should be extremely minimal with direct association. Most people won't even notice, but there may be a delay from the non-load switch as it has to send a signal to the other switch to turn on/off or dim (via Z-Wave Association or Central Scene)
  2. Non-Synced LED Bars: The LED Bars will not be in sync with one another -- this is more prominent on the dimmer as it will not show the correct level.
    1. As mentioned above, you can set the level of the non-load switch to off or 100% and disable the relay. This will at least give the switch a consistent look.
    2. You can get around this by setting up an automation from your hub, but it's still a pain
  3.  Hub Limitations: Although most hubs do, some hubs do not support Z-Wave Association or Z-Wave Central Scene Control which is required to allow the switches to talk to one another. Hubs that do support it: SmartThings, Hubitat, Homeseer, Vera, Fibaro, and Home Assistant).

Setting Up a Multi-Switch Scenario

Now that you know and understand the limitations, let's talk about how to set up a 3-Way with two smart switches (NOTE: same logic applies with a 4-Way, 5-Way, etc). This will be an overview on how to set things up and we'll create hub specific directions soon. These are listed in our recommended order as speed is impacted the further down the options you go.
If your hub supports Z-Wave Association, we recommend this as it is the quickest in terms of the switches talking to one another.

Pre-requisites:
  1. Hub must support Z-Wave Association
  2. Switch is wired per Figure 1.1
  3. Black or Red Series Switches
  4. Both switches are included in your Z-Wave network
Please setup the association on the switch not connected to the load. Let's begin:
  1. Wire the switches according to the diagram above (Figure 1.1) -- this applies to both dimmers and on/off switches
  2. Optional: Disable the relay on the switch not connected to the load (this will be the, "Master/Source" switch that will control the other switch by sending it commands)
  3. Associate the switches together via your hub (or our Z-Wave Association Tool for SmartThings and Hubitat)
    1. Master/Slave or Source/Destination: Z-Wave Association is a one way street -- in other words, you cannot have two way communication between Z-Wave devices, so as noted, you'll have to make the switch not connected to the load the, "Master/Source" switch and the other one the, "Slave/Destination" switch
    2. Group 2 & Group 4: If you want On/Off only, Associate via Group 2. However, if you want Dimming, you'll have to Associate both Group 2 and Group 4 (NOTE: Our On/Off's do not support Group 4)
Test your association. At the non-load side, you should be able to turn on/off and dim via the switch (it will send a signal to the destination switch). On the load side, the switch will actually operate as a normal switch since it's still connected to the load and the relay has not been disabled.

Option #2: Via Z-Wave Central Scene Command

If your hub supports the Z-Wave Central Scene Command Class, you'll be able to use this to have the switches talk to one another. While this is slower than directly Associating the switches together, it still is a viable option if this command does not process via the cloud.

Pre-requisites:
  1. Hub must support Z-Wave the Central Scene Command Class
  2. Switch is wired per Figure 1.1
  3. Red Series Switches (Black Series does not have the Central Scene Command Class built in)
  4. Both switches are included in your Z-Wave network
Please setup a scene on the switch not connected to the load. Let's begin:
  1. Wire the switches according to the diagram above (Figure 1.1) -- this applies to both dimmers and on/off switches
  2. Optional: Disable the relay on the switch not connected to the load
  3. Using your specific hub app or UI, setup a scene where you single tap up on the switch not connected to the load. For more specific instructions around the logic, please see our directions for your specific hub:
    1. SmartThings (requires a device handler -- hyperlink is for our LZW31-SN switch -- please search your specific model for more info),
    2. Hubitat (requires a device driver)
    3. HomeSeer
  4. For a single tap up scene, please use Button 1 (Pushed) whereas for a single tap down scene, please use Button 1 (Held) -- for the logic behind how buttons work, please see Figure 1.2

Figure 1.2 - Button Mapping for On/Off & Dimmer

Option #3: Via Manual Association Configuration

If you can set associations directly from your hub, please set the following associations:

Switch
The switch that is not connected to the load needs to have its associations set. Set a group 2 association on the non-load switch to point to the load switch's node id. For example, if your switch that is connected to the load has a node id of 7 then the association would look like this:

Non-Load - Group 2: 7

Dimmer
The same idea as above, but you need to set an association for group 2 & 4. So if the switch that is connected to the load has a node id of 8:

Non-Load - Group 2: 8
Non-Load - Group 4: 8

Option #4: Via Automation (ie: Robots, Scenes, etc)

If your hub does not support Z-Wave Association or Z-Wave Central Scene Command, there is one last way to do this, however, it's not recommended as response time may vary depending on your hub and you may press one of the switches and end up waiting 5 seconds or longer for your other switch to turn on.

Pre-requisites:
  1. Hub must have some sort of rule machine or, "if" this, "then" that program
  2. Switch is wired per Figure 1.1
  3. Black or Red Series Switches
  4. Both switches are included in your Z-Wave network
Please setup an automation on the switch not connected to the load. Since there are literally 100's of hubs out there, please make sure you understand how to create a robot, automation, or whatever vernacular your hub uses to automate your switches. The logic is as follows:
  1. When you press up (to turn on) your switch, it will send a signal to the hub to let the hub know it's on
  2. The automation you setup should say, "If the hub detects Switch A (not connected to the load) is on, turn on Switch B (connected to the load)"
  3. Setup the same automation for turning off
Again, we do not recommend this method as it can be slow.