Bob.My thinking as well. I also doubted that the water connection somehow ran under wall and through the chassis particularly as I have had a close look and can see no outlet for the copper pipe after it exited through the wall/floor. I've also looked under the sink and cannot find any "orphan" connections other than to the fresh water filter and instant hot water piping. Both are traceable. I also have a hard time believing that Airstream would run the piping over the door when there was a more direct route around behind the steps
If only there was a "circuit tracer" for water like the 12V
Thanks for your thoughts.