Boiler emits exhaust smell or flue gas odor in the mechanical room

Critical safety warning: Flue gas contains carbon monoxide. If you suspect flue gas spillage, shut down the boiler and ventilate the area immediately.

• Turn off boiler: Switch off power and close the gas valve.
• Inspect vent connections: Check all visible vent joints for separation, cracks, or missing seals. Reseat and secure any loose joints.
• Check for blockages: Ensure the exhaust termination is clear of obstructions outside.
• Room air: Verify that the mechanical room has adequate combustion air openings and is not under strong negative pressure from exhaust fans.

Professional help: A licensed technician should perform a combustion analysis, inspect the heat exchanger, and verify vent system integrity before the boiler is restarted.