A water heater is provided that heats water in a storage tank and discharges the heated water. The water heater includes a storage tank configured to store water, at least one first temperature sensor configured to sense a temperature of the water stored in the storage tank, a second temperature sensor configured to sense a temperature related to an outside of the water heater, a first heat exchanger comprising at least one heating element configured to heat the water, a second heat exchanger comprising a heat pump system and configured to heat the water, and a controller configured to control at least one of the first heat exchanger and the second heat exchanger based on a temperature sensed by the second temperature sensor and a set water temperature.