If you've already plugged it into a receptacle and see no LED activity whatsoever, we'd first recommend moving it to a different receptacle to rule out any grounding issues.
If the receptacle is powered and working fine, try performing a hard reset on the ZEN15 Power Switch. Just remember that this type of reset will erase all previously recorded activity along with any custom changes you had in place. In addition, you can only reset the device if it's already been included to your Z-Wave network.
To reset the ZEN15 Power Switch, press and hold the Z-Wave button for AT LEAST 20 SECONDS. After releasing the button, the LED indicator should flash orange and then stay solid orange for 2 seconds.
If you notice the ZEN15 Power Switch became unresponsive after you connected an appliance, we also recommend checking here to verify that the connected device is compatible with the switch. Certain devices, like 220V appliances and battery chargers, will damage the ZEN15 Power Switch.
If the LED indicator is still unresponsive after trying the suggestions above, please let us know! Our team will be happy to help.