A method for controlling the temperature of hot water through an operation of a circulation pump according to the present invention includes: judging whether a user uses the hot water; judging whether one of the circulation pump operating modes is selected; and circulating the hot water in an outflow pipe to an inflow pipe by operating the circulation pump provided on a bypass pipe connecting the inflow pipe which direct water enters and the outflow pipe through which heated hot water flows out to each other when the user uses the hot water and selects one of the circulation pump operating modes, thereby controlling a temperature difference of the hot water that flows out from a water heater to be reduced.