| 摘要 |
PROBLEM TO BE SOLVED: To prevent water from being discharged to the outside of a hot water heater by providing a blow valve on a bypass passage that bypasses an opening/closing valve provided on a hot water pouring passage located between a hot water supply circuit and an additional burning circuit for opening the valve to permit a flow to an additional burning circuit side when pressure of the hot water supply circuit side exceeds predetermined pressure. SOLUTION: In a hot water supply circuit 2, water supplied from a water supply source 23 is heated uoon its passing through a heat exchanger 21, and is eluted from a water supplycock 22. An additional burning circuit 3 includes a pump P and an additional burning circuit 3, and in a hot water pouring circuit 4 a hot water effluent side of the hotwater supply circuit 2 and the additonal burning circuit 3 are connected. On the hot water pouring passage 4 a solenoid opening/closing valve 41 is disposed and a bypass passage 5 that bypasses the opening/closing valve 41 is provide where a blow valve 51 being a kind of a check valve is provided. Hereby, when high pressure is produced on the hot water supply circuit 2, the blow valve 51 is opened to cause hot water in the hot water supply circuit 2 to flow into the additional burning circuit 3, and hence an abnormal high pressure state in the hot water supply circuit 2 is prevented and each part of the hot water supply circuit 2 is prevented from being damaged. |
