Turn off the power to the electric water heater, open the hot water faucet to drain water, open the pressure relief valve, and close the cold water valve. Then use a screwdriver to open the outer cover of the sewage outlet; use a wrench to unscrew the screw of the sewage outlet, take out the magnesium rod and drain the internal sewage and impurities. Open the cold water inlet valve, rinse the inside, and close the cold water inlet valve when no sewage is discharged. Open the prepared special cleaning agent for electric water heaters, use the provided syringe to inject the cleaning agent into the drain port of the electric water heater, and tighten the drain port. Open the cold water inlet valve, fill the electric water heater with water, and close the hot water valve to soak it for a certain period of time according to the cleaning agent instructions; when the special cleaning agent in the water heater has soaked with water for a period of time, open the hot water valve and twist it open Drain the water from the sewage outlet. When the water is drained, open the cold water again to fill it up and rinse the inside until there is no foam. Replace the special magnesium rod for the electric water heater and the sealing gasket and nut of the sewage outlet. Tighten it with a wrench to ensure that it does not leak. Cover the outer cover; refill the water and heat it. Do not use it after adding water for the first time until it is heated to about 60 degrees. At this time, you can cut off the power and drain everything, then add water and you can use it normally.