water heater

Abstract

To provide a water heater capable of performing additional heating for an amount of hot water discharged by the time when hot water supply is stopped.SOLUTION: A control unit 10 of a water heater opens a bath hot water supply valve 5 to supply hot water to a bathtub 2 and closes the bath hot water supply valve 5 when a predetermined hot water supply time passes after the bath hot water supply valve 5 is opened in a hot water supply operation mode A, detects whether or not the bathtub 2 is filled with hot water by operating a bath circulation pump 6 after the bath hot water supply valve 5 is closed, and outputs that there is an abnormality in a drain plug 2a of the bathtub 2 upon detection that the bathtub 2 is not filled with hot water. If there is an abnormality in the drain plug 2a, the control unit executes an additional heating operation mode B. In the additional heating operation mode B, the control unit calculates an amount of additionally heated hot water from an amount of hot water supplied to the bathtub 2 in a prescribed hot water supply time, and performs an additional heating operation until the amount of additionally heated hot water reaches the amount of the supplied hot water or more.SELECTED DRAWING: Figure 1

Images