This factsheet focuses on the integration hydraulics and control of central ST systems in DHC. The first part gives an overview of the typical integration concepts and operating modes implemented in the state of the art. The second part illustrates general aspects of the integration of heat pumps to achieve higher shares of ST and describes recent projects: two implementation projects (Crailsheim and Salzburg-Lehen), and one feasibility study performed by the Technische Universität Dresden.