A storage type hot water supplying system, comprising: heating means for heating a heating medium; a heat exchanger configured to exchange heat between the heating medium and water;; a hot water storage tank configured to store hot water heated in the heat exchanger a first circuit (14, 15) connecting the heat exchanger and the heating means to each other; a first pump configured to circulate the heating medium in the first circuit (14, 15); a second circuit (10, 13a, 13b, 17) connecting the heat exchanger and the hot water storage tank to each other; a second pump configured to circulate water in the second circuit (10, 13a, 13b, 17); and control means for controlling the first pump and the second pump, characterized in that the control means is configured such that, in a heat accumulating operation for accumulating hot water in the hot water storage tank, the first pump is controlled so that a temperature of the heating medium heated by the heating means and flowing out of the heating means becomes equal to a target temperature, and the second pump is controlled so that a water temperature difference that is a difference between a temperature of the hot water heated in the heat exchanger and flowing out of the heat exchanger and a temperature of the water before being heated in the heat exchanger and flowing into the heat exchanger becomes equal to a heating medium temperature difference that is a difference between the temperature of the heating medium heated by the heating means and flowing out of the heating means and a temperature of the heating medium before being heated by the heating means and flowing into the heating means. heating means for heating a heating medium; a heat exchanger configured to exchange heat between the heating medium and water;; a hot water storage tank configured to store hot water heated in the heat exchanger a first circuit (14, 15) connecting the heat exchanger and the heating means to each other; a first pump configured to circulate the heating medium in the first circuit (14, 15); a second circuit (10, 13a, 13b, 17) connecting the heat exchanger and the hot water storage tank to each other; a second pump configured to circulate water in the second circuit (10, 13a, 13b, 17); and control means for controlling the first pump and the second pump, characterized in that the control means is configured such that, in a heat accumulating operation for accumulating hot water in the hot water storage tank, the first pump is controlled so that a temperature of the heating medium heated by the heating means and flowing out of the heating means becomes equal to a target temperature, and the second pump is controlled so that a water temperature difference that is a difference between a temperature of the hot water heated in the heat exchanger and flowing out of the heat exchanger and a temperature of the water before being heated in the heat exchanger and flowing into the heat exchanger becomes equal to a heating medium temperature difference that is a difference between the temperature of the heating medium heated by the heating means and flowing out of the heating means and a temperature of the heating medium before being heated by the heating means and flowing into the heating means.