The textbook gives the basic concepts of gasified heat generating (boiler) installations and the terminology used in boiler technology, the principle of operation and device of gasified heat generating (boiler) installations. The types and device of heat generators (boilers) of their furnace devices are considered; types and device of gas-burning devices, the number and places of their installation in furnace devices; auxiliary equipment-devices for air supply and removal of combustion products, devices for water treatment, steam supply and circulation of the coolant of hot water boilers; device for thermal control and automatic regulation of the boiler installation. The issues of operation and efficiency of gasified heat generating (boiler) installations and their gas supply systems; requirements for conducting gas-hazardous and emergency recovery operations of gas supply systems are considered. Meets the requirements of the federal state educational standards of secondary vocational education of the latest generation. For students of secondary vocational education in the specialty 08.02.08 "Installation and operation of equipment and gas supply systems".