Abstract: A flue system, which may include a side flue extending horizontally out through a side of a building, the flue guard including a body with an interior surface, an exterior surface, a first end, a second end, and a channel defined therethrough from the first end to the second end, the flue guard further including fins joined to the first end and at least one stop joined to the second end, the stop being of sufficient dimension to engage the end of the side flue and method of maintaining a side flue free of debris, may include the steps of inserting a flue guard through a side flue and into a building sufficiently far to position fins joined on a first end of the flue guard at a location sufficiently far in the flue to avoid collecting frozen condensation on the fins in all natural climates.