ONE-CAN MULTI-CHANNEL TYPE WATER HEATER AND METHOD FOR CONTROLLING IT

PROBLEM TO BE SOLVED: To provide a one-can multi-channel type water heater for raising a supply hot water temperature to a set temperature in a short time in the case of starting by solely using a hot water supply. SOLUTION: In an equipment, a singly using time maximum supply mount of an upper limit amount of a fuel to be supplied to a burner 1 at the time of solely using a hot water supply with a water supply only to a hot water supply channel 20 and a simultaneously using time maximum supply amount of an upper limit amount of the fuel to be supplied to the burner 12 at the time of simultaneously using with water supplies to both the channel 20 and a reheating channel 40 of a bathtub water are predetermined. An opening control means 72 controls the supply amount of the fuel within a range by temporarily enhancing the upper limit of the supply amount of the fuel to more than the singly using time maximum supply amount from the time point of starting the singe using up to a lapse of a predetermined period.