Electronic gas water heater displays E08; unit may shut down shortly after ignition or during operation.

Safety: High flue temperatures can be dangerous. Turn off power and gas before inspection.

• 1. Inspect vent system: Check the entire vent for blockages, crushed sections, or improper materials. Ensure terminations are clear and vent length and fittings comply with the installation manual.
• 2. Check flue baffle: Remove the draft hood or top cover (on atmospheric models) and verify the flue baffle is correctly installed and not dislodged. On power vent models, ensure internal baffles are intact.
• 3. Test flue temperature sensor: Locate the flue sensor (often clipped to the flue or mounted in a well). Disconnect and measure resistance at room temperature, comparing to the manufacturer’s chart. Replace if open, shorted, or out of range.
• 4. Evaluate for scale: If the heater is older or in hard water service, scale buildup can cause excessive flue temperatures. Listen for rumbling and consider flushing the tank and inspecting the flue surfaces.
• 5. Reset and test: After correcting issues and replacing any faulty sensor, reset the control and test operation while monitoring exhaust temperature and draft.