Zigbee and 2.4 GHz Wi-Fi occupy the same spectrum. A Wi-Fi network on an overlapping channel raises the noise floor for every Zigbee device.
Decide before pairing
| Setting | Zigbee2MQTT default / advice | Cost of changing later |
|---|---|---|
| Channel | default 11; use a ZLL channel 11, 15, 20 or 25 | may require re-pairing some devices; some devices don't support channel changes at all |
| Network key | – | requires re-pairing all devices |
How to choose
- Find the 2.4 GHz channels your Wi-Fi access points (and your neighbors') actually use.
- Look up an overlap chart for Wi-Fi vs Zigbee channels and pick the ZLL channel with the least overlap.
- Alternatively move Wi-Fi: Home Assistant's ZHA docs suggest changing either the Wi-Fi or the Zigbee channel, and placing the coordinator away from access points.
- Set the channel in the configuration before the network is formed and devices are paired.
If you must change it later
- Expect some devices to need re-pairing. Zigbee2MQTT notes that a device still unresponsive several minutes after the change, and after being woken up, may have to be re-paired manually.
- Do it at a quiet time, with physical access to the devices.
- Never change the network key casually: every device has to be re-paired.