Furnace indicates flue gas sensor or flue thermostat fault, may shut down during operation

Safety: Turn off power and gas. Do not operate the furnace if a flue fault is suspected.

• Inspect flue terminal: From outside, ensure the Baxi flue terminal is clear of obstructions and installed per manufacturer clearances.
• Check condensate drain: A blocked condensate trap can cause poor combustion and high flue temperatures. Remove, clean, and refill the trap.
• Examine flue sensor: Locate the flue NTC or thermostat on the flue hood or outlet. Check wiring and connector. Replace the sensor if it is physically damaged or out of specification.
• Reset high-limit (if manual reset type): Some flue stats have a manual reset button. Once cooled and cause is addressed, press to reset.

Important: Combustion analysis and gas rate adjustment must be done by a gas-safe engineer using a flue gas analyser.