Intertherm 903107 Flue Extension – 5″ x 18″ Inside

Intertherm’s Flue Extensions aid in extending the roof jack connection to the furnace. Flue Extension 901935 features an inside diameter of 5″, an outside diameter of 8.25″ and a length of 18″. Extension lengthens the roof jack connection an additional 18″. Make sure the interior extension is below the ceiling, connections cannot be installed inside of attics.