Abstract: The invention relates to a device (1) for obtaining heat, comprising a first brine circuit (2) in which at least a first brine pump (3) and at least one heat pump unit (40) with an outside register (5) for utilizing heat of the ambient air are arranged, and at least a second brine circuit (7) in which at least a second brine pump (9) and at least a solar collector (8) are arranged, with the second brine circuit (7) being thermally connected with a heat storage reservoir (11). In order to cover the largest possible number of operating states and to ensure high thermal efficiency, it is provided that the first and second brine circuit (2, 7) can be flow-connected with each other via a first valve (24), preferably a mixing valve.