| 摘要 |
When the scheduled hot-water supply end time for the current day has expired and the amount of heat stored in a tank is not sufficient for the amount of heat required (the required amount of heat) to execute a freezing prevention operation until the next day's scheduled hot-water supply start time (YES in S48 in Figure 3), a controller executes a heat storage operation by operating a heat pump and a circulation pump until the required amount of heat is stored in the tank (S50). By means of this heat storage operation it is possible to store in the tank the amount of heat (hot water) required to execute the freezing prevention operation until the next day's scheduled hot-water supply start time. Subsequently, the controller executes the freezing prevention operation by circulating the hot water in the tank, without operating the heat pump, until the next day's scheduled hot-water supply start time (S56-S60). |
