PURPOSE: To contrive to efficiently recover residual potential heat from circulated hot-water, by providing a bypass flow path between a heat exchanger and a tank, and by keeping a circulating pump running for a predetermined time after the temperature reaches a set value and a heating device is stopped by shutting off hot-water from circulating.
CONSTITUTION: When the temperature detected by a room-temperature detector 14 reaches a set value, a controller 17 automatically closes a shut-off valve 12 in a fuel feed line 11 and a shut-off valve 16 in a hot-water forwarding circulation line 6. At this time, a circulating pump 3 is kept running for a predetermined time, feeding hot-water from a heat exchanger 4 and from flow paths in the neighborhood of it into a tank 2 via a bypass flow path 15. The pump 3 stops feeding hot-water after a predetermined time has passed. With such an arrangement, the residual hot-water in the heat exchanger 4 and in the neighborhood of it is collected into the tank 2 without radiating heat in vain, as a result the heating efficiency of a heating apparatus can be increased.
KEGASA AKISHI
YAMAMOTO KATSUMI
