Water heater attempts to ignite but shuts down with E02; burner lights briefly then goes out.

Safety: Turn OFF power and gas before servicing. Allow the combustion chamber to cool.

• Access flame sensor: Remove the front cover and burner access panel. Locate the Alpha flame sensor rod (often combined with the igniter on some models).
• Clean the sensor: Gently remove the flame sensor lead. Use fine steel wool or emery cloth to clean the metal rod until shiny. Do not bend or scratch the ceramic insulator.
• Check ground connection: Ensure the burner assembly and flame sensor bracket have a solid metal-to-metal contact with the chassis. Tighten mounting screws and remove rust or paint that may prevent grounding.
• Inspect wiring harness: Follow the flame sensor wire back to the Alpha main control board. Confirm the connector is fully seated and not corroded or heat-damaged.
• Reassemble and test: Restore gas and power, then run hot water. If the burner lights and stays on, the issue was likely contamination. If E02 persists, the flame sensor or main control board may require replacement.

If you are unsure about combustion safety or see signs of overheating, contact an authorized Alpha service technician.