| 摘要 |
<p>PROBLEM TO BE SOLVED: To resolve the problem of a conventional electric water heater, such as the electric bill becoming high, because boiling is conducted, even in the case that it will be in time if the user uses the residual hot water within a hot water storage tank until a nighttime zone begins especially in and after evenings. SOLUTION: This electric water heater is equipped with a heating element 5, which heats the water within a hot water storage tank 2, a plurality of temperature sensors 6 and 6a which detect the heating temperature, the quantity of residual hot water, and the temperature of supply water, and a current application time detection means which discriminates between a daytime zone and a nighttime zone, and this stops the current application to the heating element 5 for a prescribed time interval, until start of the nighttime zone out of the daytime zone, according to the temperature of supply water and the quantity of residual hot water within the hot water storage tank 2.</p> |
