Rheem heater Water is not hot

Problem with Rheem 40 GAL ELEC TALL Water Heater 6YR SC 82VH402
Water is not hot



If your water heater has NO hot water, then click circuit breaker

Next, click red reset button.
Turn off power.
Open cover on water heater.
If heater has 2 covers, open top cover
After re-seting water heater, insulation must be put back over thermostat to prevent cooler air from affecting thermostat.

1) Reset button is a good starting place to check water heater.
Reset clicks off for a number of reasons, including overheated water.

2) Reset will not reset, then replace thermostat.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

3) Resets clicks on, but clicks off again later, you should diagnose the problem.
Clicking reset is not a hazard 
Click the reset as often as you want until you have time to diagnose.
http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html

4) Reset is not tripped, and you still do not have hot water:
Then use tester on top two screws (T1 - T3 screws -or- 1 and 3 screws) of upper thermostat to check if you have power.

If you have power, then replace thermostat. 
If problems continue, a full diagnosis is needed as per the link above

If you need more help, add a comment and I will respond