On the pages of the proposed practical guide you will find information on the adjustment, testing and operation of water heating networks, on the hydraulic and thermal modes of heat consumption networks. Technical and design characteristics of the systems equipment are described. The procedure for determination of optimal heat loads, pipeline throughput, calculation of throttling and mixing devices is presented. Basic ways of saving heat and electric energy during operation of district heating systems are proposed. The reference manual is designed for engineering and technical workers of construction and operational repair organizations.