Just plug the device into a grounded receptacle and press and hold the Z-Wave button for at least 20 seconds. You should see the LED indicator flash orange and then stay solid orange for 2 seconds as indication of successful reset. NOTE: You may only reset your ZEN15 Power Switch once it has been included to a Z-Wave network.
After that, try including the ZEN15 Power Switch to your Z-Wave system again to see if that helped the issue. But if you're not seeing any LED activity once the Power Switch is plugged into a powered receptacle, please reach out to us! We'll be happy to help.