Have you reset thermostat on the heater, it will be the top thermostat right above the element. It will have a red reset button to press to reset. They will trip causing the heater not to work till it's reset or replaced due to thermostat gone bad. Chances are you may only have to reset it.

Please go to link below with to get some very helpful information on these topic's. If you replaced everything but the thermostat or reset it that's all left to hold out power to water heater. The thermostat is a safety device to protect the home owner. You may have had a element short out to trip it.
It will take 30 to 45 minutes to start to produce hot water after power comes back on.

http://www.water-heater-repair-guide.com/electricwaterheatertroubleshooting.html