Question about diagnosing a z-wave radio crashing issue

[simon4]

I had an issue a while back with my second floor Z-wave devices not always getting picked up by my main Hub (C8) which is mounted in the ceiling of the basement (just below the first floor). Although the issues could have been more widespread, I have two Zooz switches on the second floor that trigger rules, and they were getting missed. The one in my Master Bathroom more than the other but it is further from the hub.

So I decided to add a second C8 in the attic and moved the 10-15 devices on the second floor off to that hub. It dramatically improved the lost signals etc.

But then I noticed about once a month the Z-wave radio on Hub2 starts to act up and then crashes. Initially I notice that the rules from these switches don't trigger. I try the switch again which takes care of it on the rare times that the signal was lost, and nothing happens. I check the hub and can see no activity on the z-wave radio. I restart the radio and it comes back up and I get the notification that the radio is crashed. As reboot of the hub solves this.

My hub in the basement is running fine with about 50 devices and never causes an issue.

This sounds like an errant device, and de facto I have narrowed it down to the 15 devices that I moved to Hub 2. The devices on the second floor are generally newer and are joined with security. I have read that re-joining them without security can help to solve issues? Is that a good place to start? I could also reboot the hub every week but since the other hub doesn't require it I am not sure if this is a suitable course of action. Thanks for any advice.

[danabw]

You could start by taking a look at the device and app activity levels in logs, to see if you have any apps devices that are spamming your hub.

Also if you have any devices on that hub that report power usage, turn power monitoring off unless you absolutely need it.

Another thing you can do is choose the reboot option in the Hub menu, and in the dialogue that appears expand it and choose the option to rebuild your database.

I wouldn't start rejoining devices until you rule other simpler things. That should be able to function fine with those devices added with S2 security.

[simon4]

So I had an issue again today. The switches were not triggering rules. I checked the zwave log and it was blank. I tried each switch several times and got nothing in the log and Hubitat did not see them switch on and off.

Then I sent an on command to one of the switches from the device screen. It responded immediately and the zwave log started showing traffic. After that both switches are now being picked by Hubitat when I operate them.

As noted above this is consistent with the symptoms above. And I don’t see anything unusual in the general log. I am still trying to figure out what this means?