PUMP AND ELECTRIC HOT WATER HEATER HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To restart a pump used for various kinds of electric hot water heaters by assuring the safety of a use in case of the occurrence of a pull out and a failure in rotation even when a rotating magnetic field and an impeller are synchronously rotated. SOLUTION: The pump 4 stops by the occurrence of the pull out. At this time, the AC current flowing to an inverter circuit 14 is detected by a current detecting circuit 34 and whether or not a user carries out a hot water supply operation is discriminated by a hot water supply switch 13. When the hot water supply operation is not carried out, the operation is restarted after a prescribed time. When the hot water supply operation is carried out, the inverter circuit 14 is not restarted at least before the hot water supply switch 15 turns off, by which the user's safety is assured.