Multiple Red Dimmers (LZW31-SN) won't S2 Include

Hey all! I searched the group, but didn’t find my exact issue and support encouraged me to post here.

I have 10 of the LZW31-SN Dimmers, all on firmware v1.57. I’m running Home Assistant 2021.11.5 and ZwaveJS running at the latest versions available today - (0.1.48 add-in, 8.7.6 driver, 1.11.0 server). Hardware is an Intel NUC 10 running an Aeotec ZStick 5 Plus.

8 out of 10 of my LZW31-SN included S2 Authenticated without any problems and have been running perfectly with snappy response and fast automations. My other 500 and 700 series devices that support S2 from Zooz, Aeotec, and Leviton also included with no issues and have been running great.

I’ve tried excluding and including the 2 problematic LZW31-SN dozens of times - generally, HA hasn’t even prompted me for the DSK and the include succeeds but then warns it was only included unsecured (the unsecured device then functions without issue). I tried a coupe of times again today before this post and I was able to get the prompt for the DSK PIN, yet the device still included without security. Looking at the zwave logs shows the inclusion (many, many lines), but I don’t see anything amiss, albeit my protocol level experience with zwave isn’t great.

Ive tried resetting to factory the switches, restarting my zwaveJS, excluding first then including, and every other trick I know. I would just return them, but I already broke some of the heat-sink tabs to get them to fit in my environment.

What else should I try to resolve this? I suppose S2 isn’t critical on these switches, but the engineer in me just can’t deal with something that doesn’t work that should. :slight_smile:

Thanks - Andrew

Hey @andrew1 – did you ever resolve this? Sorry it didn’t get any traction.

For the record, I’ve seen a couple tickets with a similar issue all regarding Home Assistant.

@blhoward2 – have you seen this at all (messaging as you kindly let us know that Home Assistant supports S2 now as of 8.1.0.)?

EDIT: English bad was

We haven’t seen this specific to these devices, but as described this most often happens when the mesh isn’t great and the S2 authentication doesn’t complete in time or a packet gets corrupted in the air. I’d start with ensuring the USB stick is on an extension cable, as USB interference is a common source of RF issues. Second, do a network heal. Then try it.

If that doesn’t work then we can help if you open an issue on the node-zwave-js project on GitHub. We’d need Silly level logs to see what exactly is happening.


I believe @blhoward2 is correct in believing that there is something network-wise in the location of those specific devices that is causing issues. Are they further away from the hub or is there something that may be interfering with the signal? Sometimes it isn’t obvious that the location is the issue, but there is some kind of “Z-Wave demon” that is just coincidentally wrecking havoc.

As a test you could bring the hub closer to those devices during inclusion to see if you can get them to take.

I’d note that moving the hub is an absolute last resort as in our experience it creates all sorts of broken routes. If you must do it, absolutely do a network heal with everything back in place. Sometimes even that’s not enough for reasons unknown, though. We’ve found in dozens of cases that not using a usb extension cord is the primary issue.

Thanks, I should have mentioned in my original post that my first step to troubleshoot was to do the include right by my z-wave stick. I keep a short plug/pigtail to provide power in these instances. This inclusion method did not make any difference in my situation. I also tried doing a SmartStart inclusion for S2, same result.

Note: I just received 3 more I ordered Friday and all of them included S2 with no troubles.