| 摘要 |
PURPOSE:To improve the heat conduction for a sensor mounted on an outer wall from a sheathed heater at the abnormal heating of the sheathed heater by a method wherein a helical-shaped wire is arranged between a sheathed heater and an outer pipe so that the helical-shaped wire is contacted with the outer wall of the sheathed heater and the inner wall of the outer pipe. CONSTITUTION:When a pressure switch 15 is out of order, for instance, at time of abnormal overheating that the water from a water inflow pipe 13 is stopped and a sheathed heater 10 is still energized, the heat of the sheathed heater 10 is conducted to an outer pipe 9 via a wire 8, then conducted to a thermostat 12. On the other hand, when a handling cock is opened under the normal condition, the water from the water inflow pipe 13 is introduced to a hot-water supply pipe 14 while being heated through a helical-shaped water channel formed by the inner wall of the outer pipe 9, the outer surface of the sheathed heater 10 and the wire 8. |
