burlmart - There are 3 other members that have posted in these forums that own the model 213. They would be in a better position to answer. My model 211S has the FW tank under the dinette seat closest to the the cab. It has a drain accessed from the top very near the pump. The water heater has the bypass valves under the sink and mine has a plastic drain plug that is accessed from the outside. The coach battery on my unit sits on a platform fastened to the truck frame just a little back of the front passenger seat. You access that from the outside underneath.