Burner lights briefly then shuts off; control displays 'Flame Failure' or similar and may retry several times.

Safety first: Turn off power and gas before servicing. Allow the unit to cool.

• Clean the flame sensor: Remove the flame rod and gently clean it with fine abrasive pad until shiny. Avoid touching the rod with bare fingers afterward. Reinstall and ensure it is properly positioned in the burner flame.
• Inspect burner and orifices: Remove the burner assembly if accessible. Check for rust, debris, or spider webs in the burner ports and orifices. Clean with a soft brush and compressed air (wear eye protection).
• Check gas supply stability: If other gas appliances flicker or go out, there may be a supply issue. Contact your gas provider.
• Verify proper grounding: Ensure the water heater and control module have a solid ground connection. Poor grounding can cause erratic flame sensing.
• Test operation: Restore power and gas, then observe the flame. It should be stable, mostly blue with minimal yellow tipping. If the flame repeatedly drops out, the gas valve or control board may need professional diagnosis.