Originally Posted by email@example.com
I’m looking for a 12 volt water heater, like the Duoetta Mk2, but One that uses 120, not 240v shore power. Any suggestions?
Another possibility which uses no 12 volt power or propane, is one that operates on the engines coolant. The design is straight forward, it uses a heat exchanger to heat water in the tank sort of like your heater circuit. After you turn off the engine you'll have 6 gallons of heated water. If you need additional hot water you can let the engine idle for a few minutes and it re-heats the tank again. My Europremier RV back in 94 was equipped with one of these heaters. After we stopped for the night we always had hot water without using propane. It's a great "free Heat" design!
I would check with some marine supply houses. These coolant heaters are popular for marine installations, some have a 120 volt element for when your plugged in.
Stay Safe Mike