Relay Module or GE Z-Wave Switch

So I haven’t decided yet to either use the Monoprice relay modules or to replace my current light switches with the GE Z-Wave switch. I have a basic question since I’m new into this. In the case where you may have a 3-way switch, do you have to install a relay module/GE Switch in all of the switch locations (that control a set of lights) or can I just install in one of them? I would assume you only need to install one, but is there something special I have to do with the other switch locations?


With the GE switches, you have to have either a dimmer or toggle switch in the main location. If you’re ok losing the 3-way functionality then you don’t have to put anything in the other locations (depending on how your 3-way is wired, you may have to change a few other things, sometimes the Line comes in to one switch location and the Load comes into the other, in which case you could use one of the travelers to extend either the Line or Load wiring to the other location), but if you want to keep it then you need to use the add-on switch #12723 in the other locations. I haven’t used the monoprice relays before so I can’t comment on those.

For the GE switches, you need one main switch and then add on switches to replace the rest for that set of lights.

On the monoprice relay, I’m not familiar with it specifically, but you can potentially do just one, but it may require running more wire in the wall (at least, that’s my off the cuff thought based on the Enerwave relays that I have).

Thanks for the responses about the GE switches. They sound like a fairly expensive alternative if I want to keep full functionality of the switches (which is what I would want).

Maybe someone will comment about the monoprice relays that have installed them.


The GE switches are cheaper than other options…

So, I took a look at the monoprice wiring diagram and it looks identical to the Enerwave units that I have installed.

To retrofit one into a typical 3 way switch where line and load are in different boxes, you will need them to be located in the same box, which will use one of your 3 wires, another would be neutral, leaving you just one for signaling. I’m not sure you can design a 3 way circuit with just 1 wire available as the relay is triggered by voltage change. If your line and load exist in the same box, then it is possible to make it work.

On wiring the GE switches, you have to do the same sort of thing, but it handles signaling between the add on and base switch over a single wire.

Hopefully this makes sense…

Concerning the ‘cheaper’ option comment. Are you considering that you have to buy the GE Smart Switch, plus purchase multiples of the Add-On Switch to maintain functionality?

The cheaper option comment was in reference to the cost of other brands of Zwave switches, such as Leviton.

I realize that you’re looking at $35 for the base switch plus $18 per add on… Though you can save a few bucks with the Lowe’s renovopower coupon codes…

One other aspect is that if you’re using two relays instead of the GE Switch+AddOn, you’ll get two devices in ST. Depending on how you wire the two, you’ll need to do either a logical AND or a logical XOR between the two to determine whether the light is on or off… That may complicate your logic later down the road. The GE add-on is not “smart”, it just tells the smart switch to flip on/off.

You will only need one relay module to be able to control with both switches. Before you make your decision. The best thing to do is take a look at your wiring config. First. There are many 3 ways that GE switches will not work due to lack of neutral.

Thanks… will take a look at my wiring. The house is only 2 yrs old, so I would guess its up to code. We shall see though.

Once you start adding a relay per box there’s really no cost benefit to using them over the GE switches. Wiring-wise, it might be possible, but then you’d have a very clunky implementation that would rely on ST to control the lights. My Enerwave relays are set up to turn on another switch when powered on, and the lag is atrocious (typically 5-10 seconds) no matter what SmartApp I use (or trigger switch).

That’s true only if he can make the wiring work. If it’s the most common setup where line goes in one box and load out the other box with a 3 conductor + ground connecting them, then he will be a wire short of making that work as intended.

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I looked at one of the sets of lights which is actually a 4-way (3 switches controlling a set of lights).

From the link below, Options 2 is how mine is set up.

With that type of setup, would I need the GE Add-On Switches, or can I just have one smart switch and still have the functionality of the other switches as they are? Also, same question if I were to use one of the Monoprice relays?


I’ve done a couple of circuits like this in my house. You will need two add on switches to make the GE solution work. The install would be as follows:

  1. Assume whiteis neutral, black is hot, red is traveler.
  2. At the power source, connect line, load (both blacks in the box) to the switch. Connect red to the traveler and white to neutral, all on the switch.
  3. At the next switch, you will wire nut the two blacks that you pull off the old switch together and bury in the box. You will connect both whites and both reds to the add on switch.
  4. At the last switch, you’ll repeat step 2, though, there will only be one red and white.

Now, thinking this through for the relay…

The relay requires a constant source of power, so it will need to be in the first box. Then, the output for the relay will need to get to the light, so black and white will need to be capped off together all the way to the light. That leaves you with one red wire to achieve a 3 way style circuit for triggering the relay, which simply is not possible without an extra wire. I’m not an electrician though, so there may be others on here that have different wiring magic tricks that would work.

Schro… thanks for the detailed information. That’s what I was needing to know.