Furnace emits unusual smells (burning dust, metallic, or flue gas odor) during operation

Safety: If you suspect flue gas or carbon monoxide, shut down the boiler immediately, ventilate the area, and do not use the appliance until inspected.

• Initial use smells: Light burning smells can be normal after installation or long shutdown as dust burns off. This should dissipate after a few hours of operation.
• Check for visible leaks: Inspect around the flue connections for soot marks or discoloration indicating leakage.
• Install CO detector: Ensure a carbon monoxide detector is installed near the boiler and in sleeping areas.
• Professional inspection: Any persistent or strong odor requires a technician to check for flue leaks, gas leaks, and combustion quality.