When a burner is imported as a standalone unit or as a separately presented part, it is classified here. A complete furnace presented as a unit, even if it incorporates a burner, is generally classified under the industrial furnaces heading. If the burner is the essential character of the assembly, classification here may still apply — a binding ruling from CBP is advisable for integrated systems.

Yes. Combination burners — those capable of firing on both gas and liquid or pulverized solid fuel — are specifically covered under 841620 alongside gas and pulverized-solid-fuel burners, rather than under the liquid-fuel burner subheading (841610).