The geoTHERM domestic hot water heat pump offers the possibility of using renewable energy in a flexible way, as it can be integrated into existing heating systems simply by plugging it in (the so-called “plug and play” concept). During its use, it extracts heat from the ambient air to warm water. Natural warmth can be extracted in both summer and winter. The cool air that comes out of the heat pump can be used to cool a cellar, for example, and keep it dry. Solar energy sources can also be connected to it. geoTHERM is elegantly incorporated into the casing of the hot water storage tank along with its user interface and technical components. The coherent design concept of the hot water heat pump harmoniously brings together high technical specifications and the typical Vaillant product design.