This guide has been written by experts in the field to provide you, a consumer, with information about the use of solar energy to heat the water you use in your home. It is no secret that energy costs have been rising rapidly in the past several years, and that conventional sources of energy are in short supply. As more and more people feel the impact of the rising cost and limited availability of some types of energy, increasing attention is being given to the energy available in sunlight. No longer just a fad for some individual experimenters, no longer only a subject for scientific and engineering studies, solar energy applications are now a matter of intense interest to almost everyone. Of all of the ways in which we can capture and use solar energy to meet our needs, providing hot water is perhaps the simplest and most economical for the homeowner. Many manufacturers now make equipment and systems to provide solar-heated water, and many firms around the country are qualified to install, maintain, and service them. The Federal government and several states even provide tax credits to help cover the cost of solar energy systems. But deciding to buy and install a solar hot water system still requires you to consider a number of factors---whether the system will save you money now or in the future, what kind of system to buy and from whom to buy it, whether to install it yourself or have it installed, and similar matters. This guide is designed to provide some of the information you will need to make these decisions, and to tell you where to get the rest of the information you may need to install or have installed a satisfactory solar hot water system.