| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electric water heater capable of interrupting hot water supply to a bathtub by detecting abnormality of a temperature sensor for water entering a bath and a temperature sensor for water returning to a bath, and preventing a user from taking bath in a high temperature or a low temperature. <P>SOLUTION: Hot water supply piping 52 from a hot water storage tank 1 to a bathtub 10 and return piping 15 of an indirect heating circuit are disposed in a state that they are partially common piping 17, the temperature sensor 18 for water entering the bath for detecting a bath hot water supply temperature is disposed in the hot water supply piping 52, the bath return temperature sensor 19 for detecting the temperature of the water returning into the bathtub 10 in reheating is disposed in the common piping 17, and a sensor abnormality detecting circuit is disposed for comparing detection temperatures of the temperature sensor 18 for water entering the bath and the temperature sensor 19 for water returning to the bath in supplying hot water to the bathtub 10, and judging that at least one of the temperature sensors is abnormal when the temperature difference of more than prescribed temperature difference is found in the detection temperatures over a prescribed time. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
