| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve a problem in an electric water heater utilizing midnight-power wherein the temperature of a hot water storage can is detected by a water supply temperature detector 7 at 7:00 in the morning, and the warning is generated and displayed as non-boiling-up in a case where the temperature is below a predetermined temperature, that it sometimes takes a long period of time to find the abnormality because the abnormality does not exist in spite of the presence of service call from a user, as only the temperature at 7:00 is detected. <P>SOLUTION: This electric water heater 1 is composed of a can body 2 of which the water is heated by a heater 6, remaining hot water temperature detecting units 8a, 8b, a supply water temperature detecting unit 7, and a control part 9 for controlling a power supply time to the heater on the basis of the temperature data from the detectors. When the supply water temperature detecting unit 7 detects that the water is heated to above the predetermined temperature even only once during the power supply, the operation is regarded as normal operation with the detection of boiling-up even if the temperature is lowered, and the warning is not generated. In a case where the water is not heated to above the predetermined temperature even only once, the warning is generated with the detection of non-boiling up. <P>COPYRIGHT: (C)2003,JPO</p> |
