HOT WATER STORAGE TYPE WATER HEATER

PROBLEM TO BE SOLVED: To solve the problems in which: in a conventional one, after water supply construction, dirty water in which rust of piping and sludge and the like mixed during construction are mixed flows into a pressure-reducing valve 10 and impurity such as sludge attaches to the pressure-reducing valve 10; and a plurality of pieces of opening/closing means are used, so that costs of components becomes high.SOLUTION: A three-way valve 12 which can switch between a flow passage of a water supply pipe 2 and a flow passage of a drain pipe 11 is provided on further upstream than a pressure-reducing valve 10 which is in the middle of the water supply pipe 2. The dirty water in which rust in piping and sludge and the like mixed during construction are mixed can be drained before attaching to the pressure-reducing valve 10, and also, a switching operation can be performed only by the three-way valve 12. 【課題】従来のものでは、水道工事後は配管の錆や工事時に混入した汚泥等が混じった汚れた水が減圧弁１０に流入してしまって、減圧弁１０に汚泥等の不純物が付着してしまう問題と共に、複数の開閉手段を使用していたので部品のコストがかかってしまう問題があった。【解決手段】給水管２の途中にある減圧弁１０よりも上流に給水管２の流路と排水管１１の流路とを切り替えることができる三方弁１２を設けることで、配管の錆や工事時に混入した汚泥等が混じった汚れた水を減圧弁９に付着する前に排水できると共に、三方弁１２のみで切り替え動作を行う事ができる。【選択図】図１