Sonoff SNZB-04 (Window/Door Sensor) loosing connection

Hi there, I have some Sonoff SNZB-04 sensors but sooner or later I have to reconnect some of them. In my setups some senors will drop connection and then refuse to reconnect until they are removed and paired again. Then they will work for like 5 hours and the loose connection again. I bought some routers as suggested in this thread but it has not worked. I also dont think its a signal problem since the router is not that far away and there is even a Doorsensor that is on the edge of my house which never droped connection. The batteries are fresh.

Thank you in advance for your help!

Running on Rasberry Pi 4 with extension cable and Conbee2
Deconz Version v2.20.1
Conbee 2 Version 2.19.02 / 19.9.2022


Can you share some logs?

In #deconz you can find out how to make those.

Kind regards,

Hi Mimiix,
sure here you go!
I hope that this is not to much…


Nah, i use the search function :wink:

I found a few entries mentioning 0xE1, which corresponds with interference.

You might want to check for Wifi interference and channels. Also perhaps a longer cable?

Sure, will do. I will check the Channel interference and post the results. But one of the router is right next to one of the sensors that has dropped connection. Like 3 to 4 meters. Still possible that the culprit is the interference?

Yes, could be.

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Thats currently here on the 2.4 GHz Band.

I went to my local Hardware store and bought an even longer usb extension. I also swapt from Channel 15 to Channel 20. Lets hope that this helps…

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Sadly this night, the next Sensor went Offline.

Any logs ?

Sorry for beeing late…

These are some Current logs

Any Updates?

Log looks cleaner now. However, the On/off seems to be losing connection / having a bad connection:

  1. 19:12:22:213 0xB4E842873E5A0000 error APSDE-DATA.confirm: 0xE9 on task

So the On/Off Switch, which is also a repeater, is loosing the connection which makes the other Sensors loosing the connection aswell?

Possibly. Yes.

Does this mean I need even more Repeater?

You need to improve quality of the signals. More repeaters are generally better, yes :slight_smile:

Hi there, I think I got some news.
I noticed that the Sensors are losing the connection exactly 6h after the last opening or closing of the door or window. I switched to Homeassistant and installed the Zigbee Home Automation which is compatible with the Conbee2. In there you can find the option ‘consider battery powered devices unavailable after’. The default value in this is 21600 sec so exactly 6h. I changed the value to a ridiculous high number, and now the sensors work flawlessly. So I think the Sonoff SNZB-04 only sends a message if you trigger them.