| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater in which drain less likely stays in a heat exchanger.SOLUTION: A drain discharge pipe 10a is connected to a secondary heat exchanger 4 so as to discharge drain generated by latent heat being recovered in the secondary heat exchanger 4 to the outside of the secondary heat exchanger 4. An air passage pipe 10b is connected to an exhaust box 5. A three-way piping joint 10d joins a flow passage on the drain discharge pipe 10a side and a flow passage on the air passage pipe 10b side, and connects the flow passage after joining to a drain tank connection pipe 10c which is communicated with the outside of a water heater 1. In the three-way piping joint 10d, the diameter of the flow passage on the air passage pipe 10b side is larger than the diameter of the flow passage on the drain discharge pipe 10a side, and the diameter of the flow passage on the drain tank connection pipe 10c side is reduced after joining the drain discharge pipe 10a and the air passage pipe 10b.SELECTED DRAWING: Figure 1 |
