This module is the sixth in a series of eleven modules in an energy conservation curriculum for secondary and postsecondary vocational students. It is designed for use by itself or as part of a sequence of four modules on understanding utilities (see also modules 3, 5, and 7). The objective of this module is to train students in the recognition, implementation, and utilization of energy consumption and possible conservation in residential hot water heating and domestic hot water use. First, an introduction to the module and definitions of key terms are provided. Next, the text is presented in the following three units: (1) domestic hot water use; (2) water conservation; and (3) consider solar water heating. The information in each unit is presented in lecture format accompanied by laboratory exercises and questions/examples for class discussion. A bibliography and several charts illustrating the text material are found at the end of the module. (BM)