The invention relates to a method for controlling at least one first circulation pump (17b, 17c) of a heating or cooling system (1) having a primary circuit (2, 2a) and a secondary circuit (4, 30a) coupled therewith at a transfer point (3, 29). The first circulation pump (17, 17b, 17c, 17b') conveys a heating or cooling medium in the primary circuit (2, 2a), and in the second secondary circuit (4,30a), at least one second circulation pump (12, 17d) is located that conveys a heating or cooling medium in at least one partial area of the secondary circuit (4, 30a). The volume flow rate (formulaI) of the first circulation pump (17, 17b, 17c, 17b') is controlled in functional dependence on the volume flow rate (formula II) of the secondary circuit (4, 30) behind the transfer point (3, 29). Inthis way, a demand-based, and thus an energy-efficient control of the primary-side circulation pump is achieved. The invention further relates to a pump system, comprising the at least one first andthe at least one second circulation pump for carrying out the method.