| 摘要 |
PROBLEM TO BE SOLVED: To securely separate the contaminated water side from the service water side of a hot water heater by pouring water with service water pressure. SOLUTION: There are provided a main valve chamber 15, a separation chamber 16, a drain chamber 17, and a discharge valve chamber 18 on a hot water supply passage extending from a hot water supply pipe 7 to an additional heating circulation pipe passage 4. A pilot solenoid valve 25 is provided in the main valve chamber 15 for opening/closing an inlet side of a valve hole passage 24, and a first check valve 26 for opening/closing an outlet side of the valve hole passage 24 and an atmosphere release valve 27 for opening/closing a valve hole 41 are provided in the separation chamber 16, and a negative pressure closing valve 51 and a second check valve 54 are provided in the discharge valve chamber 18. A drain pipe 61 disposed on a bottom surface side of the drain chamber 17 is connected with a return pipe 59 on a suction side of a circulation pump 2, and a solenoid valve 63 is provided on the drain pipe 61. A motor driven two way valve 64 is provided at an additional heating circulation pipe passage position disposed on the side of a bathtub 1 from a connection part of the drain pipe 61. The motor driven two way valve 64 is opened upon pouring water, and is closed upon draining of the drain camber 17. |
