Chosen Solution

Brand new tank just installed and no new hot water coming from the tank.

Surely there is at least a warranty on this. I would contact Rheem here: http://www.rheem.com/contact.aspx Reset tripped circuit breaker or replace blown fuse. Confirm power is being provided to the electric water heating element thermostat. Test upper heating element and replace if required. If power is being provided to electric heating element thermostat, replace thermostat or heating element.

Water heater in lockout mode