A Zassenhaus ehh? Very nice!
As to the flushing/machine being used by others/turned off,, etc etc..
In that particular situation, I would suggest maybe asking everyone to simply not turn it off at all. It seems there are a few people using it besides you, and apparently, some turn it off when they're done. I say, leave it on 24/7, unless no one will be in the house for longer then a day. My rule is, if no one will be home for a period longer then 48hrs, I turn it off. But day to day, while no one is home, it stays on. The butterfly, Im almost positive, has autofill, and a thermal overload fuse, so it wont be a problem. Maybe if you dont use the water tap or steam a lot, drain the boiler once a week to refresh the water inside..(thats what I do)
Is the machine the levetta or the volumetric version? If its the Levetta, I think Erics Therm adaptor will fit on the grouphead..
But as to the flush.. Since its not your daily use/home machine and you cant just spend a few hours with it whenever you feel like it.. I suggest using the flush method outlined in the
HX Love Article. Flush X seconds past the water dance, wait 20-40 seconds, pull shot. I imagine everything is set to the factory settings, and I find that method is the easiest "plug&play" method for an HX. A little mirror, like from a compact makeup or something similar helps to watch the water dance so you dont have to bend down under the grouphead every shot you want to make.
Basically.. I would suggest asking everyone in the house to just leave the machine on all the time.
Im happy to hear you got a grinder to use with the machine...Its very lucky to have such a machine in such an environment. But, careful now.. Now that you bring fresh coffee and a proper grinder.. People are going to start to notice a difference in your drinks and theirs!
Enjoy!
P.S. I chuckled at the Vacu-vin joke.. I have one as well.