Electronic gas water heater shows E15; unit may shut down during operation, often in tight mechanical rooms.

Safety: Flame rollout is dangerous. Turn off gas and power immediately. Do not operate the heater until the cause is corrected.

• 1. Inspect combustion air openings: Ensure the louvers or grills on the heater jacket and in the mechanical room are not blocked by dust, storage, or insulation.
• 2. Check rollout switch: Locate the manual reset flame rollout switch near the burner opening. If tripped, investigate cause before resetting. Press the reset button only after cleaning and inspection.
• 3. Examine burner and combustion chamber: Remove the burner assembly and inspect for soot, rust flakes, or debris. Clean burner ports and chamber surfaces with a soft brush and vacuum.
• 4. Evaluate room pressure: If the heater is in a tight room with exhaust fans or other appliances, negative pressure can pull flames out of the burner area. Provide additional combustion air openings or consult a professional.
• 5. Professional inspection: If there is heavy soot or repeated rollout trips, have a qualified technician inspect the heat exchanger and vent system for blockage or damage.