Electric American Water Heaters unit displays E4; control unresponsive or random error behavior.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Internal control failure, Power surge damage, Moisture intrusion at control compartment

Safety: Turn off power at the breaker before accessing the control.

1. Power reset: Remove power for 5–10 minutes, then restore and observe operation.
2. Inspect for moisture: Check for leaks from plumbing above the control. Correct leaks and dry the area thoroughly.
3. Check connections: Reseat all connectors to the control board, including sensors and elements.
4. Replace control: If E4 persists, replace the electronic control board following the service instructions.

Medium 3/5

Electronic Control Board

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