Zigbee2MQTT may sometimes not start in Home Assistant, preventing your Zigbee devices from working.
This can happen due to a wrong adapter path, ZHA using the same dongle, MQTT problems, bad USB connection, or wrong adapter settings.
Fortunately, you can fix this with simple troubleshooting steps.
These include checking the logs, restarting the add-on, checking the adapter path, disabling ZHA, or restarting the MQTT broker.
In this guide, you will learn why Zigbee2MQTT is not starting in Home Assistant, how to fix it step by step, and additional troubleshooting tips if basic solutions don’t work.
Zigbee2MQTT Not Starting In Home Assistant: 8 Fixes
1. Restart Zigbee2MQTT
A simple restart can often fix small add-on problems.
Open Home Assistant.
Go to Settings.
Select Add-ons.
Open Zigbee2MQTT.
Click Restart.
Wait for a few seconds.
Open Logs and check if it starts.
2. Check The Zigbee2MQTT Logs
The logs usually show why Zigbee2MQTT is not starting.
Open the Zigbee2MQTT add-on.
Click Logs.
Look for red error messages.
Check if the error mentions adapter, MQTT, serial, or port.
Copy the error if you need to search it later.
Fix the issue shown in the logs.
3. Check The Adapter Path
A wrong adapter path is one of the most common reasons Zigbee2MQTT does not start.
Open Home Assistant.
Go to Settings > System.
Open Hardware.
Click All Hardware.
Find your Zigbee dongle.
Copy the correct /dev/serial/by-id path.
Paste it into the Zigbee2MQTT configuration.
Restart the add-on.
4. Disable ZHA If It Uses The Same Dongle
ZHA and Zigbee2MQTT cannot use the same Zigbee coordinator at the same time.
Open Home Assistant.
Go to Settings > Devices & Services.
Look for Zigbee Home Automation or ZHA.
Disable it if it is using the same dongle.
Restart Home Assistant.
Start Zigbee2MQTT again.
5. Restart The MQTT Broker
If the MQTT broker is not working, Zigbee2MQTT may fail or not connect properly.
Open Home Assistant.
Go to Settings > Add-ons.
Open Mosquitto broker.
Click Restart.
Open Logs and check for errors.
Restart Zigbee2MQTT after the broker starts.
6. Check The Adapter Type
Some Zigbee dongles need the correct adapter type.
Check what Zigbee dongle you are using.
If it is SONOFF ZBDongle-P, use zstack.
If it is SONOFF ZBDongle-E, use ember.
If it is SkyConnect or ZBT-1, use ember.
Save the configuration.
Restart Zigbee2MQTT.
7. Check The USB Connection
A bad USB connection can stop Zigbee2MQTT from starting.
Unplug the Zigbee dongle.
Wait for 10 seconds.
Plug it back in.
Use a USB extension cable.
Avoid USB 3.0 ports if possible.
Restart Home Assistant and try again.
8. Reboot Home Assistant
If nothing works, reboot the full system.
Open Home Assistant.
Go to Settings.
Select System.
Click Restart Home Assistant.
Wait for Home Assistant to start again.
Start Zigbee2MQTT.
Check the logs again.
Conclusion
Zigbee2MQTT not starting in Home Assistant can be annoying, but it is usually caused by a wrong adapter path, ZHA using the same dongle, MQTT issues, or USB problems.
You can fix it by checking the logs, correcting the adapter path, restarting MQTT, and making sure only Zigbee2MQTT is using the coordinator.
Following these steps should help you get Zigbee2MQTT running again.
Additional Reading
How To Add Zigbee2MQTT To Home Assistant
Zigbee2MQTT With Home Assistant: Complete Setup Guide
Use Home Assistant SkyConnect Or ZBT-1 With Zigbee2MQTT
Brianna is based in Minnesota in the US at the moment, and has been writing since 2017. She is currently a 3rd Year med student at the time of writing this.
