While using e-cat to make electricity in the house seems out for right now, using one for heating buildings and making hot water seems a natural application, provided it's made reliable and only needs an annual or semi-annual servicing.
To start out with, heating office buildings, hotels, apartment buildings and other large applications, and then crank out units for individual homes. Up north, I spend more money for heating than I spend for electricity in the winter.
A pure heat engine can also drive an air conditioner system or refrigerator. There are motor home fridges that run on propane (using the ammonia absorption/desorption cycle). So both home heating and cooling area possible.
The other thing that make this interesting is that the Byprodut is Copper. So you might spend $13 dollars for the zinc and get $30 for the copper.