!!
critical Rheem
Error Code E2
High Temperature Limit Exceeded.
? What Causes This
Thermostat set incorrectly or high-temperature limit switch malfunction.
✓ How to Fix It
Ensure the thermostat is set correctly. Reset the high-temperature limit switch.
Source: page 1 of the official manual
From the manual
This error code appears in:
Rheem Gladiator Water Heater