PURPOSE: To avoid to increase a condensing pressure more than necessary with respect to the heating temperature of a hot-water reserving tank and improve efficiency by a method wherein the hot-water, having a temperature lower than a set temperature, is returned to the lower part of the hot-water reserving tank while the hot-water, having a temperature higher than the set temperature, is returned to the upper part of the hot- water reserving tank.
CONSTITUTION: Water, heat by a heated pump heater 1, is returned to the lower part of the hot-water reserving tank 2 through a solenoid valve 7 until the temperature thereof arrives at the set temperature, however, the temperature thereof has arrived at the set temperature, the solenoid valve 7 is closed and the other solenoid valve 6 is opened, therefore, the hot-water is returnd to the upper part of the hot-water reserving tank 2. The temperature of the water in the lower part of the hot-water reserving tank 2 is not increased and is kept in constant, therefore, operation with a good efficiency may be continued. The hot-water, having a high temperature, is returned to the upper part of the tank 2, therefore, the hot-water is reserved from the upper part of the tank without reducing the temperature of the hot-water, the condensing pressure is not increased more than necessary and the heating temperature of the hot-water reserving tank 2 may be increased.
KIKUCHI UKICHI
FUJI SEIJI
