Here is the demo of this all brought together: youtu.be/C8q3-Lkvlis

Ultimately, I'm also attempting to begin a small business focused on providing quality of life improvements for Ford Transit owners. My wife and I love ours, and have many great improvements based on 3D printing. I'll be a bit more of a communicator here going forward, for those interested.

This timer allows me to configure a time delay after a switch is turned on that will then open the circuit when the timer runs out. 30 minutes is plenty for both systems (cooking, showering, etc.). If you need power again, just cycle the switch and the timer resets. It's pretty slick!

If you forget and leave a switch on, either the solenoid will get hot when no appliances are in use, or the water pump can continue to run if any air is in the line. Results can be leaking propane line (in a few years), or a dead pump. I just replaced the propane line, so I know it can happen.