You need to take 1/2 hour to learn basics and then test water heater parts before replacing anything.http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html
Follow the troubleshooting steps, and it will tell you exactly where the problem is.
Otherwise we can guess at 20 different things.
Water heater is 240V because you have more than 1 element.
Did you test for 240V across top two screws of upper element?
Breaker can be tripped off on one leg and 120V arrives at water heater so heater looks like it has electricity, but circuit is not complete.
The problem can be loose wire, bad 240V circuit breaker, sediment reaching lower element, bad thermostat, bad upper element, tripped ECO reset button.
Did you replace factory insulation and cover over thermostats after replacing elements?
Did you vacuum out sediment when replacing lower element?
How long ago did you replace elements? If you turned power ON before tank was completely filled with water, then you burned out the element. If upper element is burned out, the tank has no hot water, even if lower element is good.
Test the upper element:http://waterheatertimer.org/How-to-test-water-heater-element.html
See how a water heater works:http://waterheatertimer.org/How-it-works.html
And finally, why so many folks write to fixya saying they replaced both elements and upper thermostat, but they never replace lower thermostat for another $6? I have been puzzled about that since lower thermostat turns on and off each time tank temperature drops and is responsible for keeping water warm during standby hours. Lower thermostat cycles more times than upper thermostat.
Add a comment if you need specific assistance with any of the testing steps.