Please have a look at this comment:

https://news.ycombinator.com/item?id=43469297

It's linking to a website with the following explanation:

  However, perhaps inline with the German attitudes towards privacy, the BSH "HomeConnect" appliances have a no-cloud mode built into their app without any hacks required to disconnect them from the internet. They do require a one-time connection to perform key exchange of a long-live authorization key, but from then on the appliances can be operated entirely disconnected from the network.