If you use Z-Wave devices, your Z-Wave mesh is the backbone of your home automations. This mesh network is the way Z-Wave devices communicate with each other and with the Hubitat Elevation hub. Z-Wave devices build this communication mesh automatically, but it is not instantaneous. You MUST give your Z-Wave mesh time to establish itself before automating your Z-Wave devices. Automating devices too quickly can lead to frustration with routing issues. It may take several hours for your Z-Wave mesh to automatically find the optimal routing. While Zigbee devices can automatically self-heal, that feature only came into existence for Z-Wave devices with the introduction of Explorer Frames, which are intended to add similar self-healing options. For an Explorer Frame to reach its target, a number of compatible repeater nodes must be present. The specific number depends on the actual network topology and the amount of RF noise in the environment.
To maintain successful communication, all Z-Wave devices must be accessible. If you add devices near the Hubitat Elevation hub, then move them to their final location, you may experience routing issues down the road; therefore it is preferable to join your devices in their intended permanent location. Z-Wave radios operate from 865.4 MHz to 926.3 MHz, depending on which country you're in. Interference from WiFi or Zigbee devices is not an issue because they both operate in the 2.4 GHz frequency range, but devices such as baby monitors, cordless phones, etc. may cause signal interference because they operate in the same 900 MHz range,
A single Z-Wave network can support up to 232 devices, with up to 4 hops, therefore the total home coverage will depend on the amount of mains powered Z-Wave products on the network. The maximum range with 4 hops is roughly 600 feet (or 200 meters). Having one or more Z-Wave repeating devices will help strengthen the ability of your Z-Wave devices to maintain communication with the hub. Your environment, the distance to the furthest device, obstructions and device performance will determine the number of repeating devices required. A Z-Wave repeating device is one that is plugged into an outlet or powered by mains voltages. Battery powered Z-Wave devices do not repeat signals. Non-repeating devices are known as end devices, whereas Z-Wave repeating devices are routers.
Follow these procedures when discovering your Z-Wave devices to establish a strong Z-Wave network. Please be patient, as it is key to success. Once you have added all of your Z-Wave devices, the network will be very busy. Give your Z-wave mesh network time to settle. The waiting is the hardest part, but your patience will be rewarded with a reliable mesh network.
If you have prior experience with another hub, you may be familiar with the term inclusion. This is where a Z-Wave device joins the network, and the process differs slightly from Zigbee devices, which are said to pair with the hub or another device in certain circumstances. However, with Hubitat Elevation, the process of joining a Z-Wave device to the hub is almost identical. A primary difference from the way Zigbee and Z-Wave devices join a network is actually in the way they leave their former host controller, as explained in the next paragraph about Z-Wave Exclusion. See Add Device for information on how to join your Z-Wave devices to Hubitat Elevation.
Unless it is a brand-new device, Z-Wave devices must be excluded from their previous hub before they can join a new hub. Ideally you should also perform a factory reset before attempting to join devices to the new Z-Wave network. If the procedure to factory reset is not available, then you should at least perform device exclusion. To do this you will need to open up your old hub UI and follow the Z-Wave exclude procedure. If you are unable to access your old hub, you can still perform a general Z-Wave exclusion from Hubitat Elevation, even though the device has never been joined to your Hubitat Elevation hub in the first place. Anytime you want to remove a Z-Wave device, it is important to run a Z-Wave Exclude first. The process is different between device manufacturers, but generally involves pressing a button or initiating a sequence of steps on the device after putting the hub Z-Wave radio into exclusion mode.
Occasionally, you may end up with a device that was sold, given away, has ceased to function properly, or you forgot to exclude it, and now you no longer have an opportunity to exclude it from the hub. Whenever possible, you should always remove a device properly using the Z-Wave Exclude function of the hub, but if that isn't possible due to extenuating circumstances, you can force the system to remove the device. If a device is Force Removed from the hub, a so-called "ghost" node will remain that does not appear in the Z-Wave Radio Devices list but may wreak havoc on your Z-Wave network.
This is generally necessary only for “ghost nodes,” incomplete inclusion attempts, and other problems. A proper removal or force-removal as outlined above should be attempted first if a device is listed under the Device column in the Z-Wave Details table. To remove a device from the radio directly:
Navigate to Settings > Z-Wave Details.
Find the desired node (device or row).
Select the Remove button from the Status column. If you do not see this option, try Refresh once or twice (waiting several seconds or longer between each attempt). If Remove still does not appear, the hub is likely able to hear back from the device, and it can be either properly removed (see above) or factory reset (see manufacturer's instructions) and this process re-attempted. It can also be excluded (via a general exclusion) using another hub/controller, including a different Hubitat Elevation hub or any controller, if one is available.
Each Z-Wave device builds a neighbor table to keep track of which repeaters are its closest neighbors. When you initiate a Z-Wave repair, you are telling each Z-Wave device on the network to re-establish which routing devices are its closest neighbors, and therefore the most efficient route back to the hub. This also tells each device to forget about router devices that no longer exist on the Z-Wave network, or are now out of range and no longer able to be used for routing.
Z-Wave Plus is designed to not require repair, and will “self heal.” There is no magic behind this process. Z-Wave repair merely re-creates routes for nodes on your mesh. It is generally unnecessary to manually repair Z-Wave Plus devices thanks to Explorer Frames. However, it can occasionally help to run repairs on a Z-Wave Plus network to reduce the time required to update the neighbor table.
Model C-7 hubs allow a per-node repair from the device/row in the Z-Wave Details table in addition to the hub-wide Z-Wave repair option offered on all models. The per-node repair is preferred when possible.
NOTE: Running a Z-Wave Repair will not revive failed devices.
WARNING! Z-Wave repair is very network intensive since every device will be re-routed. We do not recommend running Z-Wave Repair if you are not currently experiencing delays or issues with your Z-Wave network.
You can find details on mesh performance expectations from this Silicon Labs training module.
A Z-Wave repeater or router, is a messenger that relays information, until the messages between end devices and the hub have reached one another.
Z-Wave repeaters are devices that will always be powered by mains voltages. A Z-Wave outlet is an example of a repeater acting as a relay point for devices that are too far from the hub to reliably send and receive signals. Z-Wave and Zigbee are two different wireless protocols, therefore a mains powered Z-Wave device can only function as a repeater for other Z-Wave devices, and Zigbee devices only act as repeaters for other Zigbee devices.
NOTE: Devices too far from the hub or obstructions will result in dropped connections from weak Z-Wave signals.
When a repeater is placed between the device and your Hubitat Elevation hub, the device communicates with the repeater and the repeater communicates with your hub, significantly improving performance and reliability.
Repeaters can communicate with other repeaters, to form a strong and resilient Z-Wave mesh network.
Non-repeating battery-powered devices must always have a parent to talk to, either Hubitat Elevation or mains powered repeating devices. When the device first joins the network, it will choose a parent that provides the strongest Z-Wave signal and store it in the neighbor table. Once a device chooses its parent, it will hold on until it absolutely cannot communicate with it, even if a different parent with a stronger signal is introduced into the network. Not all Z-Wave devices can select a new parent, but using Explorer Frames, some can. However, the automatic process of updating the neighbor table to keep track of the strongest neighboring repeater devices, can take several days to complete in a large Z-Wave network. For this reason, initiating a Z-Wave Repair can help reduce the time required to update the neighbor table.
Although a Z-Wave mesh has the capability to automatically establish the optimal path for devices to communicate with your hub over time, there are some design recommendations you should follow to optimize the network and achieve the best possible results.