There are several websites that display home plumbing diagrams. Roto-Rooter, DS Plumbing, Ask The Builder, For Dummies and Better Plumbers all have diagrams illustrating the basic layout for home plumbing systems.
The Roto-Rooter website has an interactive home plumbing diagram. When site visitors hover over each of the labels identifying a certain part of the plumbing system, a small informational window opens, giving details about that particular section and its function. The website also offers tips and instructional videos on how to do plumbing maintenance and repairs on specific rooms in the house and how to conserve water.
DS Plumbing shows a simple color-coded home plumbing diagram that illustrates the proper pipe and plumbing line connections in basic, common situations. The site points out that plumbing set-ups may vary greatly depending on how old the home is and whether any plumbing work has been done by previous owners of the house.
Ask the Builder shares a "rough in plumbing diagram" of a new bathroom. This type of diagram is a simple drawing illustrating where vent lines and pipes are to be installed in a home. According to Ask the Builder, a rough in plumbing diagram should show all of the pipe connections in a three-dimensional aspect, as if all the walls and building materials of the house were removed.