Ted and Nancy,
I see you've posted 3 questions at about the same time asking basic questions on how to operate the water system and hot water heater. On reflection, I think you'd do best to go back to your dealer and have them spend a couple of hours needed to demonstrate how everything in the trailer works. If you're not clear, ask questions. You might even want to videotape the session.
They can also run down what's going on with the water heater - although based on your posts, I wouldn't be surprised if you've burned out the electric heating element. If so, I wouldn't expect it to be covered as a warranty defect. If the dealer didn't give you any instruction on how to use the trailer, you might want to discuss with them whether they ought to fix it at the dealer's expense - a couple of dollars for a new element and a little of their labor.