Loved reading this thread as I decide on whether to add hot water to our minimal SMB build.
I'm seriously considering one of the portable options mentioned. We had thought to add a fresh water tank with an external shower (no grey water tank is planned). But, after reading about the extra care and maintenance, I'm hoping for a simpler option.
We often camp where water is remotely available and not heated. A hot shower would be nice after a long hike or ride. We've used shower bags in the past but there have been times when they didn't heat up.
After reading product reviews of the Coleman Hot Water on Demand system, I'm skeptical. Has anyone used any of the other systems? The Mr. Heater Aqua Cube? Zodi? Are there any that can be supplied with a spigot container rather than an open box? I prefer to keep my water supply covered and it appears that many of these systems rely on a submersible pump.
Ideally I would like a heater with the following features:
Portable so that I can use it at the picnic table or away from the van
Attachments to allow using propane from a large tank (not disposable bottles like some Zodi models)
AC or DC charging vs. disposable batteries (as long as the batteries charge! - an issue on the Coleman)
Water supply from either a hose attachment (when water is available locally) or a closed
Not a permanent van installation so it can be left at home when not needed
The Coleman fits the bill but the product reviews are terrible! The unit is too expensive to not be reliable.