tulip creek
From September 2023 until May of 2025, I used the Zen Zigbee Thermostat without issue. I use ZHA with a Sonoff dongle plus.
In May 2025, I started to have responsiveness issues with the thermostat - commands sent from Home Assistant wouldn't register on the thermostat, giving this error: "Failed to perform the action climate/set_temperature. Failed to send request: Failed to send request: <Status.NWK_NO_ROUTE: 205>". Commands sent from the thermostat, however, would be reflected in Home Assistant immediately. I spent a small amount of time troubleshooting, and then essentially moved to a Venstar T2000 mini. I've since had some time to run down the issue with the Zen thermostat, and I've become convinced that it's a bug in ZHA or Home Assistant. Obviously the error indicates that it's a network/transport issue, but I'm convinced that's because of software, not hardware or network setup.
(there was a list of troubleshooting steps here but my post was too long so I'll post them as a reply).
My three theories as to the root cause are:
- HA update changed something
- ZHA update changed something
- HA pushed a firmware update to the thermostat which caused an incompatibility.
My guess is that it's #2, but I'm not sure.
So here's where I am now: The thermostat is set up directly next to the zigbee dongle. If I remove it and then reconnect it, it will work perfectly for anywhere from 5 minutes to an hour, and then sent commands stop working. Commands sent from the thermostat to HA are reflected immediately, and the indicator on the thermostat shows that it's connected to the zigbee network.
How do I turn on the most intense level of logging related to ZHA or this thermostat so I can get more information?
Does anyone have any ideas about what might be happening? Any other Zen thermostat users with this problem? I don't like the Venstar (the temperature sensor is very jumpy and inaccurate), so I'd like to get back to using the Zen at some point.
Thanks!
craggy sluice