This technical manual provides basic information for facilities personnel regarding the operation and maintenance of small heating systems and related equipment. Generally, the manual covers low pressure steam boilers (less than 15 psig), low pressure hot water boilers (less than 30 psig), space heaters, unit heaters, and warm air furnaces. The term “small” is used in the context of this manual to differentiate from the high pressure systems and equipment that are covered in detail in TM 5-650, Central Boiler Plants. This manual makes reference to specific types of equipment commonly in use at Army installations. System and equipment descriptions contained in the manual are general in nature. Equipment manufacturers* technical literature and manuals should also be used for reference, training, and troubleshooting specific equipment.