| 摘要 |
PROBLEM TO BE SOLVED: To suppress waste of water diluting drain during short time operation such as a cooking work, and to suppress the generation of noise and prevent lowering of durability of an on-off valve 16 by suppressing frequent opening and closing of the on-off valve 16 during long time operation such as filling with hot water, in a method of controlling a latent heat recovery type hot water supply apparatus to decide an amount of water necessary to dilution of an average PH value of drain generated per set time at a heat-exchange part, to a reference PH value, and to execute dilution operation to add the amount of water in drain from the on-off valve by ON and OFF control of the on-off valve at a period of the set time. SOLUTION: A set time during second dilution operation subsequent to first dilution operation is increased to a value higher than a set time during first dilution operation to dilute drain at the initial stage of starting of combustion of a gas burner to heat a heat-exchanger. |
