What is the difference between a fireplace insert and a fireplace conversion?

A fireplace insert refers to an accessory that can be placed into existing masonry or factory-built hearth to provide supplemental heat from the combustion of wood. A fireplace conversion uses specialized techniques to change your old metal chimney liner system (with brick facing) into one using stainless steel liners instead, which will not rust out as quickly as the other type has historically done. It should also be noted that if you have older flue tiles than those listed above, they may also need replacing during this process due to years of deterioration caused by smoke acids burning through them over time causing potentially dangerous conditions.