Please Help: Zwave Hub / Driver "Failed to connect"

I can’t express enough gratitude to anyone who takes the time to help. It’s incredibly frustrating to feel stuck and unsure of how to move forward, and I truly appreciate any ideas or guidance you can offer regarding my Z-Wave issue. Thank you so much in advance!

Here’s the situation:

My Z-Wave server suddenly stopped communicating with the Z-Wave hub after running flawlessly for over 1.5 years. I have no idea what triggered the issue, and I’m at a complete loss on how to restore functionality without losing my existing Z-Wave network and settings (which include ~49 devices).

I’ll provide as much info as possible to include Logs in hopes make troubleshooting as painless as possible for those willing to assist.

At a top level, the ZWave Service is not finding / connecting to the ZWave Hub. Here is my Home Assistant version & System info:

  • Core 2025.1.4
  • Supervisor 2024.12.3
  • Operating System 14.2
  • Frontend 20250109.2

Z-Wave Hub: Aeotec Z-Stick Gen7 (Firmware 7.20.2)
Z-Wave Integration with Addon(s): The “Hub” is no longer recognized

  • Z-Wave JS (version 0.9.0) – NOT Started
  • Z-Wave JS UI (version 3.19.0) - Running

Current Error Logs from Z-Wave JS UI (I could not attach, screenshot the best I could), but what stands out to me is the…
“WARN Z-WAVE: Zwavejs driver is not ready yet, statistics will be enabled on driver initialization”

Steps I’ve tried:

  1. Reverted to a Backup during a time period that the ZWave network was functioning.
  2. Reloaded the Z-Wave Integration
  3. Attempted connection method with Z-Wave Supervisor add-on (selected and NOT-selected)
  4. URL when Z-Wave Supervisor is NOT-selected (ws://a0d7b954-zwavejs2mqtt:3000) – that results in a “Fail to connect”
  5. Reloaded Z-Wave Integration, Z-Wave JS, and Z-Wave JS UI



Please just uninstall this. Switching back and forth and leaving it installed only complicates matters. Having both add-ons running at the same time is a common failure mode, even if you say it’s not running it might be.

No amount of fiddling with the integration is going to fix your problem. As long as Z-Wave JS UI is restarting, the integration will not be able connect. You need to solve the problem in Z-Wave JS UI, then the integration will connect again.

Z-Wave Hub: Aeotec Z-Stick Gen7 (Firmware 7.20.2)

Consider upgrading to the latest 7.21.5 firmware. The 7.20.x series is known to be bad. 7.21.5 is probably better as it has addressed some (but not all) known issues. It’s also the latest version supported by Aeotec.

It looks like your USB path is set to /dev/ttyUSB0 in the ZUI settings, is that true? Have you recently installed any other USB serial devices that could conflict, like a Zigbee controller? You should always use the persistent path starting with /dev/serial/by-id/. Make sure your controller is still visible in HAOS.

Try physically unplugging and re-plugging the stick. Sometimes it needs a hard reset.

Turn on driver debug logs so we can see which command is failing. https://zwave-js.github.io/zwave-js-ui/#/troubleshooting/generating-logs?id=driver-logs

First off – THANK you so much for sharing your time! Here’s my best effort at following your steps:

  • Done. Great point
  • Good point. This is helpful is providing insight into the relationships between Integrations and Drivers. I don’t think I have the entire picture, but every problem (like this) teaches me something.
  • Done. A couple of times. I completely shutdown HA. Powered up, then plugged back in. No luck.
  • This is likely the rub. I for the LIFE of me cannot see the Aeotec Z-Stick anywhere listed in the hardware. I searched “usb”, “z”, etc… no joy. Screenshot of the Hardware Info to follow.
  • I’ve been running SkyConnect as a Zigbee controller for >1 year. And likely because of the above issue in not being able to see the z-controller in HAOS, makes it difficult to:
  1. Upgrade firmware.
  2. Using the persistent path…
    …which I believe I now understand how to set in the ZUI (I think).
  • Done. But I don’t know how to attache either “.zip” or “.log” files. What’s the best way to share the log files?

Again … thank you so very much!

Well, this seems to be the problem. I think your Zigbee stick has become /dev/ttyUSB0. Can you confirm that in the HAOS hardware listing? Settings → System → Hardware. The SkyConnect path in your ZUI screenshot is probably /dev/ttyUSB0, which obviously the Z-Wave driver cannot use.

Can you move the Z-Stick to another USB port? Maybe temporarily remove the SkyConnect and see if it works in that port?

Any pastebin site would work, people seem to like dpaste.org. However, this really isn’t necessary now if the USB device being used is the Zigbee stick.

I cannot see the Z-Stick anywhere in the HAOS hardware listing. Here are the iterations I performed:

  • Completely shutdown HA. Unplugged SkyConned USB and removed Z-Stick from extension cord to a new direct USB port. Powered everything back on.
  • Removed Z-stick, waited 10min, plugged back into another port.
  • Restarted everything … still nothing.

Here’s what I saw with the SkyConnect removed during the above troubleshooting steps:

Here’s what I saw once I plug SkyConnect back in (note the “usb” search):

To be 100% sure, at each of those steps, I went to Settings / System / Hardware (as you detailed above), and then I click on “All hardware.” From there a long list populates and then I “search hardware” using terms like, “usb”, “z”, “aeotec” – above are screenshots of those results. In a nutshell, I can’t find any reports of the Z-Stick.

2 Questions:

  1. If it’s a bad Z-Stick, how do I preserve the Z-wave network and devices so that I don’t have to remove / add / re-establish automations, etc…? Here’s my rough understanding:
  • ZUI / Settings / Z-Wave: Screenshot Security Keys & Security Keys (Long Range)
  • ZUI / Settings / Z-Wave: Export (setting.json) file is created
  1. Assuming Z-Stick hardware issue, should I replace the Z-stick with the same unit or do you have other recommendations?

Hope to figure out how to buy you a beer for all your help!

As a last resort I would try plugging the controller into another computer just to be sure it’s not host-specific.

The Z-Wave network is stored on the controller, not in ZUI. If you have an NVM backup you would simply plugin a new controller, re-configure the USB path and restore the NVM. If you don’t have an NVM backup you are out of luck, starting over is the only option.

  • Plugged into an iMac - double checked Disk Utility and no evidence of anything being plugged in. Boo.
  1. Do you have a Z-Wave controller recommendation?
  2. Is the NVM backup file not embedded in the follow options to restore?

Not sure Disk Utility is the right place to look, considering a Z-Wave controller is not a disk.

Pretty rare for a USB controller to just straight up die randomly. You might try contacting Aeotec support to see if they have any ideas.

Do you have a Z-Wave controller recommendation?

There’s a whole list at https://www.home-assistant.io/docs/z-wave/controllers/. 800-series recommended. Zooz is popular. The HomeSeer is also good.

The add-on backup is the backup of whatever files are in the data volume of the add-on. If you a) manually created an NVM backup or b) configured ZUI to make NVM backups automatically, the add-on backup will contain the NVM backup. If you did neither of those, you won’t have an NVM backup.

  • Good point. I was assuming it would at least get inventoried. Tech Support is indicating that Mac isn’t a good troubleshooting tool. Go figure - I’m making apple sauce (GRIN)
  • That was my assumption before just replacing hardware.
  • This is what I “think” I have done. I’m searching / learning how to find those files.

I’m working with them now – very responsive group!

Again – Huge THANK you!

It would be an NVM_<data>.bin file in the store/backups/nvm directory. If you made a manual backup you also would have been prompted to download it on your PC.

  • Like this? But it looks like like Apr for the last update - and all this time I thought it was in “auto backup.”

This might help someone down the road, here is what Aeotec Support recommended when using an iMac to troubleshoot integrity of the Z-Stick:

There is one thing with MacOS that you can do which is to search for a “modem” that appears when the Z-Stick 7 is connected.

MacOS - Choose Apple > System Preferences, then click “Network”. You can find Z-Stick 7 as a USB Modem device

  • Can be listed as:
    • /dev/cu.usbmodem-XXXX (where XXXX can be a combination of a number 0-9 such as 1229)
    • /dev/cu.usbserial-XXXX (where XXXX can be a combination of a number 0-9 such as 4211)
    • /dev/tty.usbserial-XXXX (where XXXX can be a combination of a number 0-9 such as 6921)

Yep, that’s it. If you haven’t made any changes to the network since last April then it would be fine to restore (some routing configurations may be out of date). If you did add or remove any nodes since then, those changes will be missing from the restore.

There’s no such feature name “auto buckup” in Z-Wave JS UI, so not sure what you’re referring to exactly. The NVM backup options in ZUI are 1) “Backup on event” which creates backups before and after adding/removing nodes, and 2) “Backup” which is a schedule-based backup.

Does the Setting – System – Backups – All add-ons (5 automatic backups). ← does this not include the ZUI controller details? This is what I was referring to as “auto” or automatic backups…

Either way, I have it figured out going forward!!

That’s the add-on backup. It includes the files in the ZUI store and the add-on settings. It has nothing to do with ZUI’s own backup functionality.

From Tech Support: “something is messed up with your drivers which i’m not certain how to fix - but a re-install of the OS and re-installation may work”

Is there another way to reinstall Z-Stick Drivers?

– Good deal. Thank you for the clarification.

Are they talking about the Mac? Can’t help there.

On Linux, including HAOS, there aren’t any drivers, it’s built-in to the kernel.

Gotcha - Tech Support was referencing HAOS. Their theory is to reload HAOS in its entirety. Is it safe to assume that reloading from a System Backup, during a period (say 3 days ago) when everything was working, would address this step?

I am highly skeptical that a re-install of HAOS using the exact same version would make any difference, That your Zigbee controller is still working seems to indicate there’s not a general problem with your USB subsystem. I don’t really know if restoring a backup is “good enough”, guess you’ll have to try if that’s the only thing left.

Did you do any HAOS version upgrades that would coincide with the problem? There have been issues related to HAOS itself and USB devices before. What device is HAOS running on?

I vaguely recall running an Update sometime between 9-11am on 28 Jan; but I do not recall if it was a Core update or something else as I was traveling when I initiated the update. I’m looking in the logs in hopes to answer that question. However, I already performed a Restore from a time period ~ 12 hrs prior to the failure.

I am running two HA setups with the exact same configuration (supporting my home and parent’s home). I do one at a time and once one HA System seems to be working then I do the other. In this case, only my HA experienced this issue.

Hardkernel ODROID-M1