RV Repair: water heater, cold side, water heater

Question
I stored my RV last winter (the first time I ever attempted this on my own, I am not mechanical at ALL)  I brought it out last week, everything seems to work fine, except the batteries are toasted, except the water heater.  I get some luke warm water, about enough to wash my hands, and then I have no more hot water.  It continues to flow from the tap; but it is just as cold as the cold side.  I don't know what to do.  Please advise

Answer
Greg, It sounds to me like you have the water heater bypass on still. Behind the water heater there should be some valves, 3 most likely. The center one needs to be closed and the outside ones need to be open, or to allow water into the heater. If you stored it you will probably remember what you did when you are reading this. I hope this helped, Bill