If you’re experiencing issues with your Zigbee network on Homey, here are advanced troubleshooting steps to help optimize performance and stability, especially in more complex environments:
Power Supply Integrity
A stable power supply is critical for Homey’s performance. An underpowered adapter can lead to instability in the Zigbee network. Always ensure you’re using a reliable adapter providing at least 2A. Power fluctuations can cause disconnections or communication failures, especially under high device loads.
Optimal Placement for RF Performance
Zigbee networks are sensitive to radio frequency (RF) interference. Avoid placing Homey too close to high-powered Wi-Fi routers or access points. Both Zigbee and Wi-Fi operate on the 2.4 GHz band, so a physical separation of at least 2 meters is recommended to reduce interference. This improves both range and signal stability.
Wi-Fi Channel Interference Mitigation
Zigbee performance can degrade if it overlaps with congested Wi-Fi channels. Use a Wi-Fi analyzer to identify which channels are being used by surrounding networks, especially if neighboring Wi-Fi networks are contributing to interference that you cannot control. Homey’s Zigbee channel can be changed if conflicting networks are unavoidable. To do this, go to Homey Settings > Zigbee and perform a Zigbee network reset, allowing you to select a less congested channel. Note that changing the channel will require re-pairing devices, so plan accordingly.For more detailed guidance on avoiding interference between Zigbee and Wi-Fi channels, visit this resource: Zigbee and Wi-Fi Interference: How to Avoid Channel Overlap.
Ensure Adequate Mesh Backbone (Routers)
Zigbee relies heavily on a mesh network made up of mains-powered devices (routers) to extend and strengthen signal propagation. When you setup a new Homey it’s critical you start with several mains-powered routers, such as smart plugs or bulbs, to ensure stable routing paths as they form the foundation of your network. An excess of early added battery-powered end devices can weaken the network’s integrity, as they don’t relay signals.
Strategic Placement of Routers for Remote Devices
Devices that are located far from Homey or behind dense walls may struggle with weak connections. To ensure proper communication, place powered Zigbee routers between distant devices and Homey to relay signals. Without this, battery-powered devices may experience packet loss or become unreachable over time.
Centralized Network Topology
For optimal network coverage, position Homey as centrally as possible in your home relative to your Zigbee devices. In larger setups or multi-story buildings, place routers in a star pattern to reinforce signal distribution, ensuring that peripheral or isolated devices maintain a strong connection.
Zigbee Chip Memory Limitation
Over time, frequent additions and removals of devices can fill the memory of Homey’s Zigbee chip, which retains information about previously connected nodes. This can lead to running out of free slots, causing instability or preventing new devices from being added. A full Zigbee network reset will clear the chip’s memory and resolve these issues. Before proceeding with a reset, ensure you have a recent backup. Homey’s backup feature will allow you to restore all your devices and settings after the reset, so you won’t have to reconfigure everything from scratch.
Full Zigbee Reset and Rebuild
If you’re still facing issues after implementing these fixes, performing a full reset of the Zigbee network may be necessary. This step wipes the network configuration and requires re-pairing all devices. Pair mains-powered devices first to establish a solid mesh network before adding battery-powered devices. A backup is crucial before this process, as restoring from it will save time and effort by re-adding all your devices seamlessly post-reset.
Congestion from Overactive or Faulty Devices
Network congestion can occur if certain devices are configured to send too many reports, or if a device is malfunctioning and flooding the network with unnecessary data. This can cause delays and affect overall network performance. To identify these problematic devices, monitor traffic patterns using Zigbee sniffer tools or Homey’s developer tools to inspect the frequency and volume of data being transmitted by each device. If a device is over-reporting (e.g., sending updates every second), adjust its reporting interval settings, or if faulty, consider removing it from the network temporarily to assess its impact.
Implementing a robust mesh infrastructure, managing memory limitations, and identifying devices causing congestion will help maintain high performance and stability across your network.
This is an interesting one, how did you come to the conclusion that the chip retains this information?
Some more info that might be useful to add: the Zigbee chip in HP2023 is also used for Thread.
This “Multi-PAN” setup is problematic, in that it can cause issues for both protocols when enabled. It will impose additional limits to the amount of devices you can add for each protocol, and a problem with one protocol (like the congestion problem you mention) can affect the other protocol.
This is why Home Assistant advises to have dedicated chips for these protocols (they use the same chip as Homey does in their SkyConnect dongle), which sadly isn’t possible with Homey.
Hi Robert.
I arrived at this conclusion based on a combination of technical understanding of Zigbee networks, documentation from Silicon Labs, and experiences shared within the smart home community, including the Homey forums and other platforms that utilize similar hardware.
Here’s how I came to this conclusion:
Technical Understanding of Zigbee Networks:
Node Table Management: In a Zigbee network, the coordinator (which is the role Homey plays) maintains internal tables that store information about all devices (nodes) that have ever joined the network. These tables include the Neighbor Table, Routing Table, and Child Table.
Finite Memory Capacity: The memory allocated for these tables on the Zigbee chip is limited. Once the tables are full, the coordinator cannot add new devices or may experience network instability.
Persistence of Entries: If devices are removed improperly—without following the correct exclusion process—their entries may remain in the coordinator’s tables, occupying space unnecessarily.
Silicon Labs Documentation:
Developer Guides and Datasheets: Silicon Labs provides detailed documentation on how their Zigbee chips manage network tables. These resources explain that the coordinator retains information about previously connected devices to maintain network integrity.
Reference: For example, the Silicon Labs Zigbee Fundamentals Guide discusses how network nodes are managed and the importance of proper inclusion and exclusion.
Community Experiences:
Homey Forum Discussions: Numerous users have reported issues where they are unable to add new devices after frequently adding and removing devices. These issues are often resolved by performing a full Zigbee network reset, which clears the coordinator’s memory.
Other Platforms: Similar experiences have been reported on other platforms using Silicon Labs chips, like SmartThings and Hubitat, reinforcing the conclusion that the chip retains information about previously connected nodes.
Best Practices in Zigbee Network Management:
Proper Device Removal: Industry best practices emphasize the importance of properly removing devices using the correct exclusion process to ensure that the coordinator updates its tables accordingly.
Network Maintenance: Regular network maintenance, including monitoring and managing connected devices, helps prevent the node tables from becoming full.
Personal and Observed Experiences:
Troubleshooting Instances: Instances where new devices couldn’t be added until a network reset was performed suggest that the coordinator’s memory was full due to retained entries.
Network Analysis Tools: Utilizing Zigbee network analysis tools can reveal lingering entries for devices that are no longer active, indicating that the coordinator retains their information.
Manufacturer Acknowledgment:
Firmware Updates and Notes: Firmware updates from device manufacturers sometimes include improvements to how the node tables are managed, indicating that this is a known issue.
Support Responses: Official support channels occasionally acknowledge that residual entries can cause issues and recommend network resets as a solution.
In Summary:
Retention of Node Information: The Zigbee coordinator retains information about devices that have been connected to the network. If devices are not properly removed, their entries remain in the coordinator’s memory.
Impact of Frequent Changes: Regularly adding and removing devices without following proper procedures can fill up the coordinator’s node tables.
Resolution Through Network Reset: Performing a full Zigbee network reset clears these tables, freeing up memory and resolving issues related to full node tables.
It sounds like Athom should know this information too, since ultimately it’s their software that’s responsible for handling (proper) device removal.
I know about the issues with the same chip (Silabs EFR32MG21) on other platforms. For zigbee2mqtt, a complete driver rewrite has been implemented to work around many issues with this chip (and even so, they strongly advise to not to use the latest 8.x firmware because of its instability), and I get the impression that the chip simply isn’t “finished” and wonder if Athom has made the wrong choice to use it for Homey (a rather telling sign is that the newly announced “LG Homey” doesn’t support Zigbee, only Thread).
If you want a quick overview of your Homey Zigbee network: Start with the Homey Developer Tools. They are easy to access and give you a good idea of device health and routing paths.
For basic device monitoring: Homey Insights is a good starting point to see device activity, though it won’t give you the full network picture.
If you need more advanced tools
If you need detailed, real-time monitoring: Tools like Zigbee2MQTT or deCONZ are excellent choices, but they require some additional hardware and setup.
For technical/development work: Wireshark with a sniffer provide the most granular level of network monitoring, perfect if you need to diagnose deep network issues.
Yes, it’s technically possible for Athom to create a function that checks for orphaned node entries in the Zigbee chip and removes them without doing a full reset of the Zigbee network.
Would be a nice feature, some other platforms have this already.
Thank you, Zigbee2MQTT devs also refers it as firmware changelog - EmberZNet adapters (Silicon Labs) | Zigbee2MQTT, so seems to be combination of SDK and also relevant chip firmware modifications.
(it’s just complementary info however I don’t think Athom will ever soon go new version 7.4.4.0 released in August but the changelog for both 7.4.3.0 and 7.4.4.0 is quite comprehensive)
