I am thinking about hot water for our van. I noted the 20 amp Arniston heater you have in this Sprinter and that you were planning on bringing in 30 amp shore power for it. What do you do for hot water when boondocking? We have one of those Coleman hot water on demand propane things which is okay but sort of a pain to move around and set unless you are staying put for a few days somewhere. Do you know about or have you heard anything about some of the marine propane units, such as the Excel ventless propane hot water heater? Any other ideas? We don't really use heat enough to justify the expense of hydronic heat with a coil for domestic hot water.
Hope all is well with you.
So . . . the simple answer is that when there's no shorepower, we use the microwave to heat enough water to wash dishes, clean up a bit, make instant coffee, etc. It's not exciting, but it's workable. The amount of draw on the battery bank when using the microwave a minute or two at a time is tolerable.
The shower we have is the Nemo Helio unit, which is particularly easy to use when we can fill it full of toasty water straight from the heater, but it's intended as a solar shower, so that's another possible way to get hot water.
The problem you have with those smaller, mount-on-the-wall ventless propane heaters (I've had two), is that the temperature rise you can get is pretty small, and the maximum temperature rise comes only when you have a minimal flow. If the water in an exterior tank is down around 40F, you'll be lucky to hit 65F with any reasonable flow. The bigger the unit, the more flow and/or temperature delta you can have, but the bigger units become hard to integrate into the camper.
I understand the issues with the cost and complexity of the hydronic units, and while some would argue for them, I think they're relatively finicky compared to propane. I thought about using one for the first Sprinter, but instead went with the propane-fired PrecisionTemp ShowerMate M-550. We put one in the first Sprinter and it was brilliant. At 1 gpm flow, it'll give up to an
88F temp rise. It did indeed give all of the hot water you could every want, as hot as you wanted. The two substantial drawbacks were the $1500 cost and, even more of a problem, the fact that, being a cube about 14 x 14 x 15 before connections, it used up pretty much the entire space under the sink.
