A.O. Smith electric water heater shows E22; water temperature is erratic

Safety: Turn off power at the breaker before opening access panels.

• 1. Verify settings: Check that both upper and lower thermostats are set to the same temperature (typically 120°F). Adjust if needed.
• 2. Check mounting: Ensure each thermostat is firmly clipped against the tank surface for accurate sensing. Re-seat if loose.
• 3. Inspect wiring: Confirm that jumper wires between upper and lower thermostats are secure and not burnt.
• 4. Replace suspect thermostat: If one thermostat appears to cause overshoot or undershoot, replace it with an OEM A.O. Smith thermostat.