HOT WATER TEMPERATURE CONTROL METHOD FOR SOLAR WATER HEATER SUPPLYING HOT WATER OF TABLE TEMPERATURE

PROBLEM TO BE SOLVED: To provide a hot water control method supplying hot water of a stable temperature even when the hot water temperature (Th) in a hot water tank is changed in some degree. SOLUTION: In controlling the hot water temperature of a solar water heater, the hot water from the hot water tank 15 is adjusted to a temperature of low level TLset not over a lower limit capacity of an auxiliary heat source unit 4, regardless of the change of the hot water Th until the hot water supply is stopped including the start of the hot water supply, in a case when the hot water temperature Th of the hot water tank 15 is less than the setting temperature Tset in starting the hot water supply, and then the hot water is additionally heated and adjusted by the auxiliary heat source unit 4. When the hot water temperature Th in the hot water tank 15 is same as or higher than Tset in starting the hot water supply, the hot water in the hot water tank 15 is cooled by the water through a control part 8 and adjusted under a condition free from the heating by the auxiliary heat source unit 4. Then the hot water from the hot water tank 15 is adjusted to TLset regardless of the change of the hot water temperature Th until the stop of the hot water supply from a time when the hot water temperature Th becomes lower than Tset, and the hot water is additionally heated by the auxiliary heat source unit 4 to be adjusted to a desired hot water temperature.