Fixing the Z-Wave crash

In our household, I automate as much as possible to make things more efficiency. And because I enjoy the challenge.

To interact with the different sensors and lights I use both Zigbee and Z-Wave. For the latter I use a Aeotec Z-Wave Plus Z-Stick Gen5 to connect the devices to my Home Assistant server.

Crash

This setup worked fine until I noticed a recurring problem. Every time Home Assistant, the Z-Wave Add-On, or the system rebooted, the Z-Wave Add-On failed to detect the Z-Stick. As a result, all my Z-Wave devices became unresponsive.

After searching online I tried various fixes, like updating the firmware on the stick, resetting the Z-Stick and re-add all the devices and a clean install of Home Assistant. Non of them worked, so I left the Z-Stick out of the system.

Reconnecting

When I plugged the Z-Stick back into the system after a reboot after an update, I noticed that the Z-Stick was recognized by the Z-Wave Add-On, and that Home Assistant could interact with the sensors again. When I tried to recreate this, unplugged the Z-Stick and rebooted the system and re-plugged the Z-Stick again, I found that the Z-Stick was indeed recognized again.

Solution

One day, after a system update, I plugged the Z-Stick back in after a reboot and it worked! Home Assistant recognized it, and all sensors came back online.

Testing further, I found that If the Z-Stick was unplugged before rebooting and plugged back in afterward, it was detected normally. If left plugged in during reboot, it wasn’t recognized by Home Assistant.

Automatings

Unplugging and replugging the Z-Stick manually was impractical, especially if I needed to reboot remotely. I needed an automated solution.

I found the Sonoff Micro Zigbee USB smart adaptor, a USB switch controlled via Zigbee (since using Z-Wave to fix a Z-Wave issue wouldn’t work).

After pairing the USB adaptor with Home Assistant (Zigbee controller in inclusion modus, and powering the USB adaptor on) it was recognized instantly.

Code

I wrote two simple automations; one that would power the Z-Wave stick off when Home Assistent shuts down and one that would power the Z-Wave stick back up when Home Assistent was booted again.

Automation Code

Power Off (Before Shutdown):

- id: "<INSERT ID>"
  alias: "<INSERT ALIAS>"
  trigger:
    - platform: homeassistant
      event: shutdown
  action:
    - service: switch.turn_off
      target:
        entity_id: switch.zwave_switch

Power On (After Startup):

- id: "<INSERT ID>"
  alias: "<INSERT ALIAS>"
  trigger:
    - platform: homeassistant
      event: start
  action:
    - delay:
        seconds: 60
    - service: switch.turn_on
      target:
        entity_id: switch.zwave_switch

Conclusion

While I never found the root cause of the issue, this workaround solved the problem. Now, I can reboot or update Home Assistant without losing Z-Wave connectivity or manually unplugging the Z-Stick.