District heating systems are the basis of the future sustainable energy system of the country. Reducing heat losses from heating networks is one of the main ways to ensure the economic and sustainable functioning of heating systems. The greatest effect for reducing heat losses is characterized by heating networks that combine the use of thermal insulation of pipelines with the use of a low-temperature coolant. This paper considers a two-pipe water system of district heating, the heat network of which is laid in impassable channels, and steel pipelines are pre-insulated with polyurethane foam. As studies of this system have shown, reducing the temperature of the coolant in the supply pipeline from 95 °C to 70 °C and in the return pipeline from 70 °C to 50 °C, i.e. the use of a low-temperature coolant, allows you to reduce heat losses from heating networks by 30%. Reducing heat losses from heating networks in the low-temperature district heating system under study allows saving money on thermal energy production with an operating life of 25 years in the amount of 35,000 Euros.