BATH HOT WATER SUPPLY SYSTEM

PROBLEM TO BE SOLVED: To detect open failure of an on-off valve for opening/closing a hot water supply passage in a bath hot water supply system having a high-temperature hot water supply function.SOLUTION: In a bath hot water supply system having a high-temperature hot water supply function by a hot water supply passage 27, a temperature sensor 88 is arranged on a further bathtub 8 side than a confluence point 34 with the hot water supply passage 27, in a hot water pouring passage 26, and detects hot water temperature supplied to the bathtub 8. When open failure occurs in a hot water supply solenoid valve 75, during a hot water supply operation, according to a leakage flow rate with a minimum opening of a hot water supply flow rate regulating valve 70, high temperature water is supplied to the bathtub 8 by the hot water supply passage 27 from a can body 10. A controller 200 detects the open failure of the hot water supply solenoid valve 75 on the basis of the history of detection temperature by the temperature sensor 88 during a period in which a valve close command is issued with respect to a hot water pouring solenoid valve 60 and the hot water supply solenoid valve 75, and a heating operation by the can body 10 is being executed. 【課題】高温差し湯機能を有する風呂給湯システムにおいて、差し湯経路を開閉するための開閉弁の開故障を検知する。【解決手段】差し湯路２７による高温差し湯機能を有する給湯システムにおいて、温度センサ８８は、注湯路２６において、差し湯経路２７との合流点３４よりも浴槽８側に配置されて、浴槽８へ供給される湯温を検出する。差し湯電磁弁７５に開故障が発生すると、給湯運転時には、差し湯流量調整弁７０の最小開度での漏れ流量に従って、缶体１０からの高温水が差し湯路２７によって浴槽８へ供給される。コントローラ２００は、注湯電磁弁６０および差し湯電磁弁７５に対して閉弁指令が発せられており、かつ、缶体１０による加熱動作が実行されている期間において、温度センサ８８による検出温度の履歴に基づいて、差し湯電磁弁７５の開故障を検知する。【選択図】図１