Re: Water heater location
One surefire way to confirm you have a hot water tank is if you have a hot water tank breaker in the power panel for shore power. If that slot is populated with a breaker, you more than likely have a hot water heater. That and warm water from the left hand tap.
Start from the freshwater holding tank and follow the lines. The freshwater holding tank will more than likely be in the engine compartment. On the lowest point of the tank will be an outlet line. This will first lead to a pressure water pump. The outlet will go to each cold tap. If you have a hotwater heater, then it will also go to the water IN on the hot water tank. Just get in there and start following lines. If you're not sure where the water tank is, follow the water deck fill line. That will go from the water deck fitting to the highest point on the freshwater tank. As will the water tank vent line.
Best of luck