PURPOSE:To obtain a safe and stable hot water feeder, by providing a temperature controller with a hot water temperature safety unit which delivers a signal for setting a burner at the minimum burning amount forcibly when the quantity of supplied water detected by a supplied water quantity sensor falls below a predetermined variation of the quantity of water. CONSTITUTION:A temperature controller 7 comprises a feed forward control unit 12, a hot water temperature safety unit 13 and a valve driving circuit 14. When a signal of a water quantity sensor 3 indicates that the quantity of water falls below a predetermined level, the hot water safety unit 13 detects the same and delivers a signal to the valve driving circuit 14, whereby a burner 1 is controlled to be set at a minimum burning quantity irrespective of a signal of the feed forward control unit 12. Since a feed forward control is applied, the transient characteristic of hot water feeding is improved, and thus the fluctuation of the temperature turns little even when there is a change in setting, a fluctuation in the quantity of water, a variation in the temperature of water or the like. Moreover, a rise in the temperature caused by a delay in the response of the water quantity sensor occurring when the quantity of water decreases is eliminated by the hot water temperature safety unit, and thereby safe employment can be secured.
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