| 摘要 |
PROBLEM TO BE SOLVED: To provide a storage water heater capable of lowering frequency for executing water quality improvement processing.SOLUTION: At water quality improvement processing timing when non-low temperature duration time for continuing the state where a temperature within a set low temperature range is not detected by a tank upper hot water temperature detection means St exceeds low temperature set allowable time, an operation control means 5 executes the water quality improvement processing to suppress decline in the water quality of hot water within a hot water storage tank 2. Along with the execution of the water quality improvement processing, the operation control means 5 resets the non-low temperature duration time to be zero. When a temperature of hot water supplied or a temperature of hot water in the upper part of the hot water storage tank 2 is below a determination reference temperature, a hot water supply heating means 24 heats the hot water to a heating reference temperature capable of improving the water quality of the hot water. The set low temperature range is a range which is less than the determination reference temperature. |
