| 摘要 |
PURPOSE:To prevent surely no-water heating even with water having large specific resistance by disposing a corosion preventive electrode connected to a no-water heating preventive device and a conductive material having the potential baser than the potential of a steel tank of a water heater to said steel tank. CONSTITUTION:The corrosion preventive electrode 2 connected to a DC power source 3 is disposed in the steel tank 1 subjected to an enamel treatment in a manner as to insulate electrically the electrode from the tank and the no-water heating preventive device 4 consisting of a burner control device 8 connected to a relay 5, a transistor 6 and a resistor 7, etc. provided to the circuit thereof is disposed therein to detect the voltage generated in the electrode 2, by whichj the no-water heating is prevented in the water heater constituted by providing a water feed port 10, a hot water feed port 11 and a burner 9 to the above- mentioned tank 1. The conductive material 12 consisting of Mg, etc. having the potential baser than the potential of the tank 1 is further provided in said tank so that the device 4 is operated always normally. |
