Some people are going to find reasons to migrate a Z-Wave network by hand from one Hubitat Elevation hub to another one. There are steps you can take that will make this a little bit easier than just starting over. In particular, one wants to preserve automations that use Z-Wave devices, and not have to redo them. This would useful for migrating from a C-4 to a C-7. For C-5 to C-7, one can use the Hub Protection Service and avoid all of this work.
First of all, familiarize yourself with this document: How to Build a Solid Z-Wave Mesh
You want to start with your devices closest to the hub and work your way out when building a new network. When you are migrating, you may want to keep the old hub working while building the new one. This will take some planning, as you don't want to just rip out the old mesh from the center, as that is likely to bring it down. Think of your mesh as directional lobes from the hub center. Do one lobe at a time. Think about the physical relationships between Z-Wave devices. In my house I had basically 3 directions I could work in, so I did those one at a time.
The first step is to restore a backup of your old hub to the new hub. Having both running won't be a problem because the Z-Wave radio in the new one has no paired devices. As you migrate, it gains devices at the same time the old hub sheds devices, so there remains no conflict. But, be aware that some other things will only work with one hub at a time, such as Alexa or GH, mobile app, etc.
To move a Z-Wave device, use an external device or the new hub to exclude it from the old hub. DO NOT use the old hub to do this, as this would destroy your automations, that you may want to make reference to. I find either a Minimote or Z-Stick to be a handy way for doing the exclude step, much easier than using the hub to do.
Steps are as follows:
- On the new hub go through every Z-Wave device (they don't work yet), and change its DNI by prepending the letter B to the beginning of the DNI.
- Exclude a device from old hub.
- Reset the device per its instructions.
- Join the device to the new hub. When it joins, give it the label "A Remove", and save the device. Then click on the device in the join page, which opens a new page showing the device. Make note of its DNI, and change its DNI by prepending A to the beginning of the DNI; hit Save Device.
- Open the same device, the original one whose DNI starts with B. Edit its DNI to be the noted DNI of the added device, and hit Save Device. At that point, that device is now connected to all of its automations.
- Remove the device called A Remove, whose DNI starts with A. This was actually the joined device but we've now assigned its DNI to the device used in automations, so we don't need it anymore. It was called A Remove so that it would handily be at the top of the Devices page, and you'd know to remove it.
Proceed in this manner. We are changing the DNIs to get the devices 'out of the way' of the newly joined devices. We don't want the restored backup device DNI to be the same as a newly joined device DNI. This DNI is assigned by the Z-Wave radio stack, and we have no control over it. So by changing all of the old devices to have an invalid DNI, we get them out of the way. Then, by changing the newly joined device DNI (after noting its real DNI) to another invalid DNI, we are getting it out of the way when we change the original device to have its new DNI. Finally, we deleted the temporary place holder joined device, as it is no longer needed.
All of this takes time and care, but for me this sure beat having to open every app that uses a Z-Wave device and track down its new device, and avoids having to rename devices in the migration. What we end up with is the same system we had before, but where individual Z-Wave devices have different DNIs than in the old system.
Note: Some complex Z-Wave devices (those with child devices) will not work with this method. Locks will not work with this method, as they need to join with a secure handshake.
