| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a water heater 1 which can prevent a lack of a hot water if a set pressure is, for example, high and a using hot water quantity is much in case of increasing or decreasing the using hot water quantity due to a change of a set pressure of a pressure reducing valve 3 and a relief valve 4, which prevents unnecessary boiling of a daylight time zone if the set pressure is low and the using hot water quantity is small and which can reduce a running cost. SOLUTION: The water heater 1 comprises a hot water storage tank 2, a heating means 5 for raising a temperature of the hot water of the tank 2, a pressure detecting means 11 for detecting a hot water supply pressure of the tank 2, and an energizing time zone judging means for judging a daylight time zone and a night time zone. The heater 1 further comprises a controller 9 for automatically changing a boiling start of the heating means in the daylight time zone based on a detected value of the detecting means 11.</p> |
