The Lochinvar & A.O. Smith 100109675 Flue Baffle Assembly is a genuine replacement component designed to optimize heat transfer and improve combustion efficiency in compatible commercial and residential water heaters and boiler systems. It works by directing hot flue gases through the heat exchanger, allowing more heat to be absorbed before the gases exit the vent. Used in select Lochinvar and A.O. Smith HVAC and water heating equipment, this flue baffle assembly helps enhance energy efficiency, supports consistent system performance, reduces heat loss, extends equipment lifespan, and promotes reliable operation.