Z-Wave lighting issues

Starting a new topic instead of hijacking this one: Is Z-Wave / Hubitat really suitable for real time lighting?

I have a brand new Hubitat C7 deployment with about a dozen Zooz Zen 7x dimmers and switches. Z-Wave control of the devices is unreliable to the point where I cannot use it for any real time scenario.

In troubleshooting, I've found that issuing simple on/off commands from the hub (device interface view) works very reliably when I pause a few seconds between commands. If I spam on/off quickly enough, it's as if the system becomes overloaded: The device stops responding, or behaves erratically over the next 30 seconds or so, until things settle down. The Hubitat logs will often show a flood of repetitive status events (e.g. "Dimmer was turned off"), exceeding the actual number of commands issued, during this overloaded state.

The issue is exacerbated when trying to operate groups of devices. Toggling on/off on a group of four devices just once is usually enough to overload the system.

Finally, it's not just an issue "spamming" commands. Sometimes Z-Wave commands are just plain laggy, and a device doesn't respond for several seconds. This seems to happen most often when the system has been idle for a while.

I've noticed that, while the system is in the "overloaded" state, I can still control non- Z-Wave devices (Hue Bridge) from the Hubitat with excellent response times. This suggests that it's not the hub itself is overloaded; rather, it seems like an issue with my Z-Wave network or devices.

I'm looking for troubleshooting suggestions on how to proceed here: How to gather diagnostic logs to pinpoint any potential root causes, how to interpret the information on the Z-Wave Details page, anything. I've already updated the Z-Wave Firmware on the Hubitat and performed a Repair, so I'm really not sure what else to try.

As a next step, I'll try relocating the hub to a more central location just to see whether it makes any difference, though I doubt the wife will approve a Hubitat sitting on the mantle :slight_smile: But it's currently located nearby a Hue and Lutron Bridge, which have both worked flawlessly for central control at that location for several years. (I understand Z-Wave is a different protocol, but it doesn't instill confidence in the technology if it's going to be that sensitive to the physical surroundings and home layout... we'll see...)

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I think this interpretation is correct.

This would also suggest a z-wave radio specific issue.

There are a few things you could post that would help:

  1. The full content of you z-wave details page as a screenshot.
  2. Download/install @tony.fleisher's z-wave mesh tool, and post a screenshot of the Z-Wave topology with and without non-repeaters being hidden. The native topology map doesn't give the option of hiding non-repeaters.
  3. Under Logs, screen shots of your Device Stats and App Stats.

I've noticed that the "stats" column on that page seems to reset each time I reload the page. Would it be more useful if I did some "stress tests" while that page was open?


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I'll try to figure out the z-wave mesh tool shortly, but for now, here's the details currently available through the Hubitat logs/settings pages.

I'm curious about the Z-Wave details stats -- when those things update. I've actually got 2 browser tabs open right now -- don't remember when I loaded/refreshed each of them -- that are showing different values.

Z-Wave Mesh Details from 3rd party z-wave mesh tool:

I just looked at my zwave mesh, and tried to do some comparisons.
On your chart, I noticed a few lines sticking out like a sore thumb.
You have some devices with a RTT STDDev of >300 ms.
I don't have any greater than 90.
Start loooking at those devices to see if they are responding. Are they healthy? Could there be something wrong with them?
Living Room Cam Dimmer
Kitchen Under Cabinet Cam Dimmer
Kitchen Pendants Dimmer

I also don't have an RTT average over 50. You have several twice that.
RTT average is the time it takes for HE to send a command and get a response.
Also, I noticed from your Zwave Details page that Kitchen Under Cabinet Cam Dimmer had a RTT Avg of 450ms!!!! That's incredible - there may be something wrong with that device!!!
Perhaps if that device is located close to other devices (so it's not a mesh issue), perhaps you could exclude that device, and the re-pair it. Perhaps the original pairing was faulty. Or the device itself is faulty.

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dont know if this helps you - but I had similar experience not too long ago also a new setup C7 Z-wave only, decent looking mesh mostly Zooz Zen77 and 76 - even the support folks here looked at my logs and said everything looked good. What ultimately resolved my issues was just opening the breakers to all the switches that were acting up (even dimmers that have the airgap switch - removing power at the breaker seem to net better results). knock on wood its been about 6 weeks now and I've been about 99% (a couple of minor hiccups, but not repeatable)


Your mesh looks decent and no obvious reasons for a poor Z-Wave experience. With that being said, all eyes turn to individual devices. Have you updated the firmware on your switches? Are they spinning power reports uncontrollably? With the number of devices you have, you shouldn't be overwhelming the radio that easy, although if all are set to report power very frequently that might happen.

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I mean, sure, there could be something wrong with half of my new Zooz devices. Or there could be something wrong with the hub itself. I'm not sure how I'd diagnose that.

Physical controls on the devices work great. Operating a single device at a time via Z-Wave is pretty reliable, too, as long as commands aren't issued too quickly. Things go haywire when commands are issued too rapidly, e.g. operating a group of devices. It feels like the network is just really flaky...

But I'm really trying to quantify those feelings with hard data. Was hoping that this data might lead to some smoking guns, e.g. "node X is a bottleneck," or something like that. But when the entire table is highlighted in red, I guess that's not a good sign.

I can certainly try that. We're finishing up a remodel, including an electrical panel upgrade, so power has certainly been bounced a lot in recent weeks. Doesn't instill confidence: If the mesh miraculously self-heals after a power cycle, seems like it could just as easily break down again the next time we lose power. I would hope Z-Wave would be more robust than that...?

Amazon just delivered the wifi dongle, so I'm going to relocate the C7, do a Z-Wave repair, and see whether that makes any difference.

I can tell you that is nothing wrong with the hub, but that makes it harder to pinpoint which device misbehaves. I've had a similar case last week that was traced to a switch with a loose wire that was a backbone repeater for many other devices. Accidents like that can turn any mesh into a nightmare, not only Z-Wave.

Ok, I'll proceed down the road of upgrading firmware on individual devices and see if that makes any difference. Zooz' versioning information is a little bewildering...


Version 1.0, 10.10, 10.20, 2.0... mmmkay... I guess I'll need to read the fine print on the device hardware itself to make sure I grab the right firmwares. And I hope the upgrade process isn't too onerous. Guess I'll find out soon.

Can you elaborate on how you did that ? Is it just pulling of the small piece physically ?

may i also suggest something?
If you accidentally had the power to the hub go out (you mentioned that the power had been up and down), perhaps you need a soft reset.
A soft reset is called for when your internal database has been screwed up.
Doing a soft reset will not screw anything up, so it's an easy fix (if it works).
An easy way to tell if it worked, is to do a complete zwave repair after doing the soft reset. Then look at the RTT average numbers again. If they are much reduced from before, you may have fixed everything!

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@YBee are you asking about the β€œair gap” if so yes that is just a small tab on the switch that pulls out - on my Zooz switches it’s only on the dimmer not on/off … but I would advise powering off at the breaker instead

With zooz it is easier (and perhaps more difficult for some) than this....

To get the firmware (at least last time I did it), you need to create a ticket with them with the order number, model, and current firmware version for each device and they will tell you what firmware version you need to updated to (unless you ask for something different) and provide the instructions on how to download each file.


The stats should only reset each time the hub restarts (but it might look like it happens each time you load the page if you only look to it after a restart).

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They will still do this. Alternatively, you can setup an account now that gives you access to all their firmware.

Thanks, yup, I gained access to their OTA firmware and am beginning the (agonizingly slow) process of updating firmware on devices one by one.

The first couple have taken almost an hour each to transfer the firmware, and to be thorough, I also plan to exclude/re-include each device afterwards, as recommended by Zooz.

I sure hope there's a payoff.

And possibly a soft reset?

And after all the updating a complete zwave repair?