A regulating method for a heating and/or cooling system uses at least one load circuit (6), through which a fluid as a heat transfer medium flows and switches the at least one load circuit (6) on and off in dependence on a room temperature in a room to be thermally regulated by the at least one load circuit (6). A feed temperature (Tmix) of the fluid fed to the at least one load circuit (6) is set in dependence on the relative switch-on duration (D) of the at least one load circuit (6). A manifold device is also provided for a heating and/or cooling system with a control device for carrying out such a regulating method.