illumino Dimmer Switch requires AC Neutral connection for it to be power and used in your network. Before you purchase illumino Dimmer Switch, ensure that both AC Neutral and AC Live are present in the gangbox.

If illumino Dimmer switch is wired with AC Neutral, it will not power or control the connected load. 

If your gangbox only has AC Live available, then you may need to consider using Nano Dimmer ZW111-A instead. You can find more information at this link on how to wire Nano Dimmer without neutral