Here's what to try if your dimmer goes offline or is unresponsive to Z-Wave commands:

Your RGBW Dimmer is a Z-Wave Plus device that has range of 100 feet (line of sight). With that said, interferences like large furniture, thick walls, and metal elements can shorten range. Ultimately range is determined by the specific structure of your home and the strength of your mesh network. If you're seeing connectivity issues, we first recommend healing your Home Assistant network. This function refresh the connections between your hub and devices so that the hub can find the most efficient route to each device.

1. Click on the Z-Wave Control Panel in Home Assistant
2. Under Z-Wave Network Management, click Heal Network

If healing the network didn't help get your RGBW Dimmer get back online, here are some other things that may help:

1. Try excluding and re-including the device directly from the installation location. Similar to the idea behind healing the network, it's possible that the hub hasn't found the most efficient communication route to the dimmer; exclusion can help revitalize these connections. 
2. If you have a Z-Wave signal repeater available, try including it in a spot halfway between the dimmer and hub. A signal repeater is any Z-Wave device that doesn't rely on battery power - switches, relays, smart plugs, or dedicated repeaters. If the issue is caused by interference or range, a signal repeater can help strengthen and stabilize connectivity. After adding the repeater, it's a good idea to heal your network once more. 
3. While annoying, you can also try bringing the Z-Wave hub closer to switch. After moving it, exclude and re-include the RGBW Dimmer with the hub in the new spot. If it includes successfully, stays connected, and is responsive to remote commands, it's possible the previous location was out of the hub's range or there are too many interferences in that particular area.
4. If none of the above helps, try performing a hard reset on the unit and trying the inclusion process again. 

If none of the above solves the problem, please let us know! We're always here to help.