Steve, hey there are 7 (seven) valves to the water system, =water tank,water pump pressure line, water heater,electric toilet(if equipped), hot water line next to the galley sink, cold water line and the city connection. And a word of advice to any camper, never leave your drainage valves open when hooked up to the sewage lines, the sewage smell will enter your Home Sweet Home and permeate the air . open your valves when its time to Drain and then Close them.