One amongst the numerous challenges in the field of District Heating (DH) consists of reducing the supply temperature of the water pumped from the central plant into the network. This would be beneficial for several reasons, one of which is the fact that the amount of thermal losses along the pipelines would decrease, thus enhancing the energy efficiency of the network itself. A proper rise in the mass-flow rate injected from the plant should be taken into consideration though, to compensate for the aforementioned temperature reduction, as stated by the First Law of Thermodynamics (FLT). The introduction of Thermal Energy Storages (TES) in specific points of the network – to be filled with hot water during night hours, i.e.