The link Peter send, the first post gives you the answer.
In my opinion, you hardly ever need two homeys. Choose your network zigbee or zwave or both and buy as many repeaters to get a descent mesh. Repeaters are all none battery devices. I use many smart plugs. Which work quite nice. Setting up the mesh will take some time. So after all your repeaters are installed, restart Homey and wait an hour. Most of the time your mesh will be quite nice. Remember zigbee and zwave are two totally different meshes. In that case you need repeaters for zigbee and zwave.
