| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater that can efficiently restrain scale from forming depending on operating conditions.SOLUTION: The water heater comprises: heating means 55 that heats water conveyed via a water inflow pipeline 64 from a lower part of a hot water storage tank 57; a circulating pump 63 that is arranged in the water inflow pipeline 64 and pumps the water from the lower part of the hot water storage tank 57; a hot water outflow pipeline 65 that introduces the water heated by the heating means 55 into an upper part of the hot water storage tank 57; and scale inhibiting means 68 that is arranged in the water inflow pipeline 64 and adds a scale inhibitor 67 to the water to be pumped into the heating means 55. As the temperature of outside air decreases, the concentration of the scale inhibitor 67 contained in the water flowing into the heating means 55 is increased. Because the solubility of the scale inhibitor 67 in the water can be adjusted depending on the operating conditions of the water heater, scale can be efficiently restrained from forming without wasting the scale inhibitor 67. |
