If you have Professional, you can create silent installation of avast! Home Edition but primarily it is designed for Proffesional Edition.
So if you want to create silent installation for home users you will have to change “Serial” key in the created Admin.ini file. You will have to enter activation key of Home Edition.
This is by design: you need enhanced user interface to create silent installation. To start enhanced user interface you need Professional Edition activation key - so created Admin.ini will contain this key, so you need to change it.

Note: silent installation contains bug in current version. It will not restore activation key on target machine. Updated version should be available this week