To connect your Mill WiFi device to your Amplifi HD you need to do 1 change (activate "Separate WiFi SSID). Please do the following:
1) Click the image of your Amplifi HD on the home screen of the Amplifi app to get to "Settings"
2) Click on "Wireless"
3) Activate "Separate WiFi SSID". Please remember to save by clicking the checkmark in the upper right corner
4) Then you connect your smartphone (the one you have the Millheat app installed on) to your new WiFi network: "XXXXXXXX-2G" (this WiFi network has the same password as your original netwrok)
5) Then you open your MIllheat app and connect your Mill WiFi device
Please note! You can not deactivate "Separate WiFi SSID" after successful connection with your Mill WIFi device, but you can connect your smartphone back to your usual WiFi network.