Zooz (or other) relays vs switches?

Last week I installed my first smart switch, a Zooz ZEN76. Lots of back and fourth with Zooz (who is great, BTW), some hiccups... but got it!

Now I'm starting to look towards the other areas of my home, and wondering about relays. I see so much talk about Shelly online... but, regardless... what's the general overview of a Switch vs Relay?

I live in a modern townhome so neutral is everywhere. I have zero dimming switches (though there MAY be a place or two I want to have dimming functionality...) and I have a lot of 3-way switches.

One of the first things that comes to mind with a relay is that I assume "Up" and "Down" aren't always what you'd expect, given the extra logic behind the switch? But then this is always the case with 3-way switches anyway...

Seems they definitely save on space, are cheaper, you get to keep your existing switches...

I guess you lose some of smart features like double taps/holds/lights on some of the smart switches? Based on what I'm reading it sounds like the zooz works with 3way setups, which is good to know.

I'm guessing there could be some confusion resuming from a power outage? Switch says "on" but maybe it was turned off via z-wave? Seems like a minor/non-issue to me.

Anything else to know/consider in choosing a smart switch vs hidden relay?

One difference between "relay" vs "switch" is:

  • Relay has mechanical contacts, there is a click when actuated. Can often be used for devices other than lighting. i.e. starting coffee pot etc.
  • Switch has semiconductor outputs, makes no noise and is often rated only for lighting.

However this is not guaranteed universal, You should check with Zooz on the devices you select.

Well I have learned that the zooz zen76 I just installed definitely clicks. Started a separate thread confirming it haha

At least as of right now I’m only looking in terms of lighting

So opening the whole debate of “do I go buy more smart switches” or “do I go buy smart relays”

One potential problem with the hidden relays is the space required in the boxes. The relays are small but they do take up room in the electrical boxes. Even in a modern townhome with good wiring the space in the box can get tight.


Some factors that swayed my decisions (not all apply in OP's case):

  • Necessary wires are only in a junction box or fixture box (relay)
  • 4-way control of a lamp outlet (relay)
  • Fan control (Zen71)
  • 3-way lighting (Zen76)
  • Scene control (Zen7x)

So, in retrospect, it is fair to say that I only chose a relay when a switch would not easily satisfy the job with existing wiring. I have not yet encountered a situation in which the aesthetic was an issue (i.e. needing to keep a novel appearance for switches).

And the noise. Especially if you have a "scene" where several lights are turned on or off at the "same" time. Sounds like crickets.

Some of my Zooz switches AND dimmer click especially if they are controlled via zwave commands.

That being said, all the old switches in my house were toggle style and Ivory in color (from 1997). All back stabbed for wiring and some broke in half while I was trying to remove them they were so cheap. I wanted to switch to decora style and white anyway so smart switches was the way to go.

I have one 3-way for the basement stairs where there is no neutral in the switch boxes. So here I went with a ZEN51 installed in the fixture. Well actually its installed outside the fixture but all the wire connections are inside the box. This is due to space, you think these would fit in the boxes but it really is a stretch to jam them in there if any more than 2 sets of wires are in the box. I also have 4 zigbee relays for the bulb sockets in the basement that normally operate off only pull cords.

Personally I would stick with the switches if white decora works (or you can get color kits for Zooz now). Also if you have a neutral in the box to use the switch,

Reserve the relays for edge cases if you want to keep some existing fancy switch for looks, or if you need to put the device in the fixture itself.


My current musing is converting a table lamp so that the pull chain switch can still be used without disabling remote operation. A ZEN51 might get involved if I can figure out how to decouple the switch. Small gauge wire could maybe be fit in the existing riser for the dry contact trip. But that's the subject for another thread.

You need to hook up with this guy: Zooz Zen51 and Zen52 - double relay & dry contact - #43 by user3420

He is going to attempt the same thing.

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Thanks. I read that. A switch glued to the existing switch might not fly in the aesthetics dept. There was a guy on the SmartThings forum who hacked a 3-way switch to send a momentary, I believe, to a smart relay of some sort. His 3-way switch wasn't a pull chain though. His also did dimming, far as I can recall, which I'm not interested in. A trip to the hardware store and some switch surgery is in my future. He had to drill out some rivets to get at the guts, far as I can recall. You'd think there'd be a small market for something like this vs the big clunky things you usually see.

Sorry for taking the thread afield.

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I went with all switches vs relays:

  • Same "user" experience (i.e. the Wife Acceptance Factor or WAF)
  • I have the switches such that the little LED is on when the switch is off (makes it easy to find in the dark..and if you have a box with 3 or 4 switches provides a nice nightlight)
  • Most of mine are on/off switches, but I do have dimmers for ceiling lights, etc.

My general philosophy is Z-Wave for actuation (switches, door locks, garage doors, etc.) and Zigbee for sensing (motion sensors, leak sensors, contact sensors for doors, etc.)

My switches are the GE/Jasco, and my dimmers are Inovelli. What's nice about both of these devices is if you have 3/4/5 way switch setups:

  • GE makes a "dumb" repeater switch rocker switch
  • You simply connect the traveler wire between the main switch and dumb switch, and the dumb switch takes on the personality of the main switch (or dimmer)
  • The wiring is simple

I have a few Zooz devices (I have their combo dimmer/switch setup to control ceiling fans...dimmer for light, switch for fan on/off), but I don't like they way these wire up in 3/4/5 way.

Cheers...and welcome to your next hobby!

The biggest advantage to the Zooz 3-way setup is COST which I think is what they were going for. If you are like me and seldom use the excessive amounts of 3-ways in the house it is great. The "addon" switch is just a regular 3-way that I think costs around $3 (or you can keep your existing 3-ways switch if they don't need to be replaced). If you do want the addon to be perfectly matching you can just get another identical Zooz device and wire it hot with no load, then link them together with associations or an app on the hub.

I got lucky and the majority of mine the main switch was in a good spot and the "addon" switch was more out of the way, and we don't use them very often. I have one or two spots where I have been contemplating adding a second smart switch so the rocker behavior is the same as the main.

If cost is of no object then I agree the GE / Inovelli way of handling it is a little nicer of an outcome.

I prefer switches in most places. I like that the top button is always on and the bottom button is always off. Another aspect I like is that with my Innovelli switches is that there is a little light that indicates if they are on or off, but they can also be adjusted to do things like show notifications. I also like the multitap feature on my switches.

I have all GE/Jasco switches. I recall for the basement, I repurposed a couple 3-way existing traveler wires to supply neutral to the switch boxes and used direct associations.

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Well I've only got the one zooz to speak of, but how are the inovelli/GE way better? It REQUIRES you to have a second switch which is just a smart-dumb switch anyway. When I can keep mine?

The one I installed was for my entryway lights+stairs. Happened that the main wires were at the top where I initially preferred and all works fine. In retrospect it MIGHT have been nice to have the "main" switch at the bottom for the sole reason of having the light down there should I come home at night, lights don't come on automatically... light switch is easily found. But also not the end of the world I guess.

If I went with inovelli, could I put the "primary" switch at the bottom/front door with the light? I'm guessing no because the extra power line is coming in to the main box at the top?

When you are using the slave switch, you have to put the primary switch where the power comes in from the circuit breaker box.

This requires you to actually determine where this is...and for 3/4/5 way it can be tricky.

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So then yeah how is Inovelli/ge any better? They REQUIRE purchase over another switch. Have to open both boxes up and do some wiring?

My zooz I only had to mess with one.

"Better" is subjective.

Traditional 3/4/5 Way switches always annoyed me as the switch could be in the "on" position but the light could be off.

With the "add on" switch, press up is always on and press down is always off. If the switch supports double taps, etc., the double tap also works for the "add on" switch.

  • This leads to a high WAF (Wife Acceptance Factor) use case for my house
  • When the doggie gets let out in the dark and scary morning, she can "double tap on" any of the 4/way switches and all of the exterior backyard lights come on
  • When doggie decides to come back in she can "double tap off" a totally different switch and they all go off.

For dimmers, the addon on switch becomes a dimmer at the 3/4/5 way location. this improves the WAF at my house as all switches act the same.

The "add on" switch is about 30% the cost of the full smart switch.

So...like I said..."better" is subjective.

I did say if cost is no object..., that was the key point, not just that they are better.

The slave / addon switch usually has the same design and functionality of the main switch. May vary by manufacturer and I only have Zooz so I am only speaking of what I have seen online. To a regular user they may even know the difference between the main and slave switches, they will look very similar and ideally perform the same functions with the same style of paddle.

If you are happier to save some money and use the existing 3-way switch then Zooz is a good choice. If you do decide you want a matching addon switch later you can get another Zooz and pair them up using a rule on the hub. Probably would still be cheaper or near the same cost compared to one of the other brands + their special addon switch.

I got to the word "Ivory" in this sentence and was saying to myself, 'yep, know that story' and then I saw 1997, not 1950, 60, 70, not even 80 !

And then I got to the word "cheap" and I thought to myself....it USE TO BE that we replaced 'old electrical' cause it WAS INDEED old, maybe outdated, but not necessarily cheaply made.

EDIT: Point being, why can't we build things to last anymore...wouldn't we all pay for some things to be quality, safe, and lifetime? And why does "top-of-the-line/premium/commercial" grade have to be the wildly over priced means to get it?

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