Make sure there is water in the heater before doing anything. Flip up the lever on the temp/pressure relief valve at the top to make sure. You turn on the heating element with no water in the tank, and you just burned up your new element.
1. Has it worked on electric before.
2. Are you plugged into an 120 volt power source and/or is the water heater plugged into an outlet (on the backside) and is the circuit breaker turned on that controls the water heater (120 volt AC stuff has circuit breakers, 12 volt DC has fuses)
3. Is the electric switch in the bottom right hand corner turned on
4. Have you checked the ECO hi limit/thermostat behind the rubber cover to see if it is tripped or burned out? have you pushed the reset button on the left thermostat?
I know this sounds weird, but are you sure you replaced the element and not the anode rod. I have a reason for asking such.