On our most recent IoT Podcast, Don called in to explain that the Z-Wave device furthest from his hub is occasionally dropping off his smart home network. He’s thinking of adding a Z-Wave front door lock and has added one Z-Wave repeater already. Unfortunately, the sporadic problem isn’t yet solved.
Although Z-Wave devices create their own mesh network, with each device acting like a repeater to other Z-Wave devices, the radios don’t have much range. You can expect around 30 feet of range in a best case situation. Walls and other obstacles will limit that range. Don also has the troublesome device near a metal washer and dryer, which isn’t helping either.
The other challenge is that Z-Wave uses unlicensed 900 MHz spectrum in the U.S.
A number of older devices such as cordless phones, baby monitors and some remote controls use this frequency too, which could be causing network interference. If you have any other 900 MHz devices, try to turn them off, or better yet, replace them with something that uses Wi-Fi or Bluetooth, to remove interference for the Z-Wave devices.
Our next recommendation is to remove all of the Z-Wave devices from the hub and then rebuild the Z-Wave mesh network one device at a time from the hub out. This way the furthest device will have peer devices nearby when the network is rebuilt.
If that doesn’t help, it’s probably worth spending money on another Z-Wave repeater or two. We found a two-pack for around $55 on Amazon that should resolve the issue but rebuilding the network is a free first step. Unfortunately, it’s difficult to provide a universal solution that will work since every smart home has a different configuration, various devices and other variables. But following these steps have a good chance at getting the best performance from your Z-Wave devices.