No hot water does not always mean a new tank. On electric water heaters, the upper thermostat, lower thermostat, and elements fail more often than the vessel itself.
Kill power at the breaker, confirm the tank is full, then use a multimeter to check for 240V at the upper thermostat and continuity across each element. If voltage is present but an element is open, replace the element. If there is no call for heat at the thermostat, replace that control.
Stock thermostats, elements, and T&P valves are ready to ship from NRA Parts.
