Zwave JS: Connection error

hello,
I see same error message in previous articles but can’t find how to solve it.

issue:
Zwave failed to connect, all the zwave devices becoming non responsive.

Error message “Failed to connect: Cannot connect to host localhost:3000 ssl:default [Multiple exceptions: [Errno 111] Connect call failed (::1’, 3000, 0, 0), [Errno 111] Connect call failed (127.0.0.1, 3000)]”

To solve temporarly the issue: I reboot home assistant. It will work a short while and then back to error message.

what I tried already:

  • Changing the zwave dongle, from Aeotec gen5+ to sonoff dongle PZG23
  • adding a USB extension cable
  • changing the power supply
  • changing from Zwave js to zwave js ui
  • downloading logs & checking with AI
  • Rebuilding routes
  • Changing ws URL: localhost / Server IP / ws://core-zwave-js:3000 / ws://a0d7b954-zwavejs2mqtt:3000 (when using zwave js ui)
  • Changed the USB port
  • restarted numerous times

Some are mentionning rolling back the firmware to 1.6 but can’t find it.

I am about to throw away all zwave modules so would love some help.

Configuration:

  • Firmware zwave: 7.23.1
  • Server URL: ws://core-zwave-js:3000
  • Home assistant OS on raspberry PI3
  • Core 2026.3.3
  • Supervisor: 2026.03.2
  • Operating system 17.1
  • Sonoff Zigbee on ttyACM0
  • Sonoff Zwave on ttyUSB0
  • RFXcom on ttyUSB1

This morning:

  • processor: 5%
  • Memory: 0,7GB/1GB

Anything I should check?

After upgrade to Zwave JS UI to version 7.1.0 I have got the same situation. Restoring to the restore point which was made by the upgrade did not work. Restoring to a full back-up made last night did also not remediate the problem

I get the message Failed setup, will retry: Failed to connect: Cannot connect to host core-zwave-js:3000 ssl:default [Connect call failed (‘172.30.33.2’, 3000).

The log info selected for Zwave JS UI shows normal behavior.COntinuously updating values. The Zwave JS log shows : Failed to open the serial port: Error Resource temporarily unavailable Cannot lock port.
The entities are not available for display in the dashboard.

I do not know what to do next, because a restore did not help. And I have the feeling that it is a configuration mismatch caused by the upgrade.

You can’t use both the core app and Z-Wave JS UI community app at the same time. Pick one of them. Currently you are using the core app. Recommend staying with that since it includes Z-Wave JS UI and the community app will eventually be deprecated.

Sorry, but I am not sure what that means. My configuration always worked until today. I have 27 Zwave nodes and hundreds of entities configured.

I can still see all the nodes and is I select zwave JS and these are all updated. See included picture My dashboard refer to the entities which seem not to be available anymore.

I am very confused why this happened. Please provide steps to take (hopefully not reconfigure all the dashboards and the automation) to make it work again. Thx in advance.

You said:

Then you also said:

Which means you have actually been using the Z-Wave JS core app, not the community app. Installing the Z-Wave JS UI community app should not have been done. This dual app configuration has never worked, and you were just lucky.

I think you can just uninstall the Z-Wave JS UI app, but you should make a backup before doing so.

Thanks for fast responses. Unfortunately…

I uninstalled Zwave JS UI. I now have no longer the ability to check from the menu on the left with the many details. And entities are (still) no longer provided by the zwave JS integration.

It seems that 16 out of 27 devices are not included. With 627 entities in an unknown state a reconfiguration effort will be immense. For now I will revert back to the the backup made just before removing zwave JS UI and will execute a restart. A lot related to zwave will not work but at least other essential automations will. I will do further research tomorrow.

All suggestions a still welcome. It disturbs me very much that this update caused these problems while everything worked well yesterday. Even if it should not have.

Just enable it on the app settings.

It seems that 16 out of 27 devices are not included.

I think that’s a bad translation. In your case it surely means 16 of the devices are “not ready”, because your Z-Wave JS UI community app made a mess of things. Try restarting the core app first. If that doesn’t work, you may need to re-interview them. Look in the Web UI for a better view of things.

It disturbs me very much that this update caused these problems while everything worked well yesterday. Even if it should not have.

This is actually a normal occurrence when you are running both apps at the same time (invalid configuration). Search the forums and you’ll find numerous topics.

Thanks again. Okay I follow you. I uninstalled JS UI again and restarted.

Please give me clue where to configure that. I would have a better view on all nodes.

I will take some sleep now. Will be back tomorrow morning.

Go to the Z-Wave JS app page. There’s a toggle to enable it.

hello I am using only the core, I tried to switch to js ui to see if it would solve it, didnot, so i uninstall it

in the app section I no longer have js ui, it was put and removed to try to solve the issue but issue happened before I tried it.

My reply was to the other poster to address their problem, which seems unrelated.

This message would indicate a configuration problem, as it should be connecting to ws://core-zwave-js:3000 instead. What happens if you fix that?

Check the app logs, if the integration cannot connect it would be an issue there. Memory on a RPi3 is not usually enough with multiple apps and integrations, so that could be a concern.

Thank you so much. Your analyses were correct:

Just for others

  • I de-installed ZWAVE JS UI app. I watched the netwerk and some nodes did not become online right away (17 out of 27)
  • Waited (went to sleep). During sIx hours remaining nodes were reinterviewed. Many nodes are now online. (5 out of 27 are still left and being reinterviewed. 4 out of 5 are sleeping).
  • I am sure I will get the remaining back in the network again
  • I needed to toggle the side bar on because the uninstall of zwave js ui removed it. Now I can see the details of the nodes again.

Thanks again for helping and your fast reactions.

I ve got that but js ui is not in the app list