HEAT PUMP TYPE HOT WATER SUPPLY APPARATUS

PROBLEM TO BE SOLVED: To eliminate the possibility of running out of hot water because a boiling-up quantity is reduced when a large quantity of medium temperature water is left in a hot water storage tank.SOLUTION: A heat pump type hot water supply apparatus includes: the hot water storage tank 1, to which a water supply pipe 2 and a hot water discharge pipe 4 are connected, for storing hot and cold water; a heat pump type heating means 23 for heating hot or cold water taken out of the lower part of the hot water storage tank 1 and returning the heated water to the upper part of the hot water storage tank 1; and a control means 41 starting boiling-up by the heat pump type heating means 23 in a predetermined time zone, terminating the boiling-up when the temperature of water flowing into the heat pump type heating means 23 is a predetermined boiling end temperature or higher, and determining the produced situation of medium temperature water in the hot water storage tank 1. The control means 41 changes the predetermined boiling end temperature to a lower temperature when having determined that the produced amount of medium temperature water is small over the past predetermined period.