STORAGE TYPE WATER HEATER

To solve a problem in a storage type water heater whose bypass circulation passage passing through a heating bypass pipe 23 shares a part with a water supply passage of a water supply pipe 4 that when a boiling-up operation in an early start stage and a hot water supply operation are carried out simultaneously, circulation in the bypass circulation passage is stopped.SOLUTION: A storage type water heater includes a selector valve 22 for switching the flow of hot water to a branch point from a heating return pipe 18 to a heating bypass pipe 23, and switching control means 25 for executing control of the selector valve 22. When a hot water supply operation is carried out when the number of rotations of a circulation pump 20 during a boiling-up operation is in a low rotation state, the switching control means 25 causes the selector valve 22 to close a heating bypass pipe 23 side and open an upper side of a hot water storage tank 2 so as to reduce an influence of water supply pressure by the hot water supply operation, and circulation pressure by the circulation pump 20 driven in the boiling-up operation, thereby preventing circulation in the boiling-up operation from being stopped even if the hot water supply operation is carried out.SELECTED DRAWING: Figure 2 【課題】加熱バイパス管２３を通るバイパス循環経路が、給水管４の給水経路と一部を共用している貯湯式給湯機において、沸き上げ運転開始初期と給湯運転が同時に行われると、バイパス循環経路での循環が停止してしまう。【解決手段】加熱戻り管１８から加熱バイパス管２３への分岐点に温水の流れを切り替える切替弁２２と、切替弁２２の制御を行う切替制御手段２５とを有し、沸き上げ運転時の循環ポンプ２０の回転数が低回転状態である場合に、給湯運転が行われると、切替制御手段２５は、切替弁２２を加熱バイパス管２３側を閉じて、貯湯タンク２上部側を開くようにしたことで、給湯運転による給水圧と、沸き上げ運転で駆動する循環ポンプ２０による循環圧力との影響を軽減し、給湯運転を行っていても沸き上げ運転の循環が停止してしまうのを防止することができる。【選択図】 図２