LZW31-SN unable to dim after upgrade to firmware 1.61

When I updated one of my Red Series dimmers to firmware 1.61, it lost the ability to dim. It would appear to dim normally according to the indicator light, but the actual load would be full on if the level was > 0, and then full off once it “dimmed” to off. The behavior was the same regardless of whether I used the paddle or z-wave commands to set the level.

When I reverted back to firmware 1.52, the problem disappeared. I picked 1.52 because that’s what was running on most of my other dimmers. It’s probably what I upgraded from, but I’m not totally certain.

I have another red dimmer that is working totally fine on 1.61.

  • I used the “binary firmware updater” custom device handler on my hubitat C-5 to do the updates.
  • I updated both targets 0 and 1.
  • The dimmer is running with a neutral wire in a single-pole configuration, driving three LEDs that haven’t changed at all.
  • After it started having problems, I thought perhaps the firmware got corrupted, so I installed 1.61 (and MCU 1.45) again, but there was no change.
  • I purchased the dimmer in 2019, so it’s a fairly early model. But I think the other dimmer that’s working on 1.61 is from the same batch. I can confirm that if you think it’s important.
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Did you check that parameter 52 was set to 0 or disabled?

In addition to that, you may need to toggle Parameter 52 to re-initialize it. Some firmware updates have caused this parameter to clear even though it may appear to be set


I think it was a configuration/parameter issue. Thanks for pointing to parameter 52. The behavior was exactly what I’d expect with that set to “on/off”. When I reported last night that it was back to normal after the firmware downgrade, I was wrong. It was working normally from the switch, but ignoring z-wave commands. Sounds like remote protection was somehow enabled, even though hubitat didn’t think it was. After toggling the setting, it works normally again.

Is there a way to tell the switch to restore all parameters to default values, without needing to exclude and re-include it (and set up all my automations again)? Or does a factory reset also reset the zwave connection information?

The only way to reset all params is to do a factory reset. AFAIK excluding the device also preforms a factory reset.

A factory reset will exclude the device but the hub will still have the device registered. It will show up as offline/unavailable. You’ll need to manually remove the device from the hub.

Gotcha. Maybe I’ll add some code to the driver that creates a button to force-sync all parameters or something. If I do, I’ll share it.

It’s definitely annoying that sometimes random parameters get changed after a firmware update, in a way that causes the device on the hub to be out of sync with the actual switch. But at least there’s a simple solution.

One day I want to try to replace failed device in zwavejstoMQTT just to see if that would work or not. If it did, I could reset the device and then replace it with itself.

What if the above suggestion does not work?

Can you be more specific? What have you tried, and what happened?

What hub are you using?

After updating the firmware you might want to force a change on each parameter. One way to do this is to change each parameter to a value you don’t want, and click save/configure. Then change them all back to what you do want.

I did successfully update the hubitat firmware updater driver to add functionality to save/restore parameters before/after upgrade, but I haven’t uploaded the code anywhere yet. Is that something people would be interested in using?

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I would be interested in that. For me I updated reds blacks switches and dimmers via hubitat. All the switches were fine but all the dimmers stopped responding. I b have my own thread but I ended up excluding, defaulting and reincluding all of them.