Boiler shows E14; may be associated with condensate or flue issues; unit shuts down

Safety: Turn off power. Condensate is mildly acidic; wear gloves and eye protection.

• Inspect trap: Locate the NTI condensate trap at the base of the heat exchanger. Remove it carefully and check for sludge, debris, or scale. Clean thoroughly with water.
• Check drain line: Follow the plastic drain tubing to its termination. Ensure it slopes continuously downward, is not frozen, kinked, or blocked.
• Prime trap: Reinstall the trap and fill it with clean water to ensure proper sealing before restarting the boiler.
• Level switch: If your model has a condensate float or level switch, test it for free movement and continuity. Replace if stuck or defective.