PURPOSE: To use a heater to a minimum extent by providing a controller to switch the input of the heater in a plural stage according to the difference between a set temperature and the detected temperatures of a temperature sensor in a heat pump type hot water supplier.
CONSTITUTION: In a heat pump type hot water supplier consisting of a hot water storage tank 1 having a heater 2 inside, a heat pump 6 and a circulating pump 7, the input of the heater 2 is switched in a plural stage by a controller 4 according to the difference between a set temperature and the detected temperature of temperature sensors 3 and 3'. For the reason, heating for insufficient portion can be made by all the input of the heater 2 when the difference is great but by small input of the heater 2 when the difference is small. The heater 2 can thus be used to a minimum extent.
OHAMA MASAHIRO
YAMAGUCHI KOUICHIROU
