| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electric water heater in which the residual quantity of hot water can be informed stably even if the temperature sensed by a temperature sensor for sensing the residual quantity of hot water fixed to a hot water storage tank fluctuates due to the effect of outdoor temperature or usage of hot water. SOLUTION: When the icon of residual quantity of hot water 'Z1' is lighting (Step S1), it is unlighted (Step S3) only when a sensed temperature T1 is lower than 45 deg.C continuously for 5 min (Step S2A). Since a decision is made whether the icon 'Z1' is lighted or unlighted after the sensed temperature T1 is monitored continuously for 5 min, the icon 'Z1' is prevented from being displayed or not displayed frequently and repeatedly even if the sensed temperature T1 fluctuates in the vicinity of a threshold value and the residual quantity of hot water can be informed stably.</p> |
