| 摘要 |
<P>PROBLEM TO BE SOLVED: To reliably detect an abnormality of a heat exchanger caused by scale clogging etc. of the heating heat exchanger of a storage water heater. <P>SOLUTION: The storage water heater includes an operation control means 28 for controlling rotational frequency of a heating primary circulating pump 11 so that detection temperature T2o of a heating secondary outlet temperature sensor 22 becomes target going temperature and controlling a heating secondary circulating pump 13 at predetermined rotational frequency. The operation control means 28 calculates heat exchanger high temperature side temperature effectiveness η by dividing a value obtained by subtracting primary side outlet temperature T1o from primary side inlet temperature T1i by a value obtained by subtracting secondary side inlet temperature T2i from the primary side inlet temperature T1i, and determines that the heating heat exchanger 5 is abnormal when the calculated temperature effectiveness η is lowered to a predetermined certain value or less. <P>COPYRIGHT: (C)2010,JPO&INPIT |
