The possibility to control the return temperature leads in a quick way to another trend in the analysis of energy systems namely the so-called “low temperature district heating” (LTDH). At the moment transition is observed from the 3rd generation (80/40 oC) to 4th generation (50–55 oC/25 oC) systems of district heating. The return temperature in district heating networks is a very important parameter to be controlled and of great impact on the economy of the network operation. It influences the transmission heat loses, pumping power etc. One way to obtain lower return temperature is to introduce optimal connection of heat receivers. In the developed model the module consisting of the supply pipeline and the heat receiver is introduced as a novelty. Theoretical analysis presented herein concern specifically the connection in the network of two heat exchangers heating the same space which are connected in parallel or in serial combination. Using combinations of such modules analysis can also applied in finding for example an optimal connection of additional houses in the district heating network. As a result is shown that the parallel connection results in lower return temperature and the need for much less pumping power. Model can be used in designing a new network or for incorporation of a new heat receiver into the existing network, such as for example connection of the additional house/dwelling. A mathematical model for the basic module of the district heating network in the form of the heat exchanger together with the suppling pipeline was described. Multiplication of such modules allows to design more sophisticated network.