Connect the water tank's plug or wiring to the proper receptacle jacks on the back side of the step-down transformer. Use a screwdriver to loosen and tighten the wire contacts if a standard plug is not used for connection. Step down transformers all vary slightly, so be sure to read the user manual of your step down transformer.
Connect the power cord from the step down transformer to the wall electrical socket.
Turn the power switch of the step down transformer to the on position and then power up the hot water heater.