This military-developed text consists of four volumes of materials for use by those studying to become apprentice heating system specialists. Covered in the individual volumes are the following topics: related subjects (basic electricity, electrical controls, pipe and copper tubing, the principles of heating, fuels, and fuel systems); heating systems (space heating-unit heaters as well as burner, warm-air, and hot-water heating); and central heat plants (high temperature water, steamplant operation, steamplant maintenance, and external and internal water treatment). Each chapter is organized around criterion learning objectives with readings, criterion test items, and answers. The volume review is also keyed to the objectives, but no answers are provided. (MN)