Device for water supplying by three-hole water-storage electric water heater when water cut-off

The utility model relates to a water using device of a three-hole water-storage electric water heater, which is used when tap water is cut off. A cooling water inlet (2) of a water heater, a hot water outlet (3) of the water heater and a sewage draining hole of the water heater are arranged below the water heater (1). A tee joint (5) is arranged on the sewage draining hole (4), a drain cock (6) and a pipe fitting (7) with external threads are arranged on the tee joint, and an interface (8) is arranged on the pipe fitting (7) with external threads. An air guiding tube (10) arranged above the interface (8) passes through the pipe fitting (7) with external threads, the tee joint (5) and the inner hole of the sewage draining hole (4), and is vertically inserted into the water heater (1). When the tap water is cut off, a power supply of the water heater is switched off and an inlet valve of the water heater is closed, an air exhaust nut (9) is unscrewed, and the water can be used by opening the drain cork (6).