The FLEXYNETS project on low-exergy district heating and cooling systems has been started in summer 2015 in the framework of the European H2020 program. The project aims to develop a new generation of intelligent district heating and cooling networks that reduce energy transportation losses by working at temperature levels lower than 40 °C. Reversible heat pumps and chillers are used at laboratory scale to exchange heat with the DHC network on the demand side. In this way, the same network can provide contemporary heating and cooling. FLEXYNETS solutions integrates effectively multiple generation sources (including high- and low-temperature solar thermal, biomass, cogeneration and waste heat) where they are available along the DHC network. Two network types are considered in simulation: the classic supply-return type and the single-pipe system. This paper describes possible operation strategies and some control aspects related to the second network type.