Sealing Flue Pipes for an Oil-Fired Furnace

Oil furnaces rely on the combustion of gas fumes to create heat that is then distributed through the house. Oil is effective as heating fuel, but burning it releases hazardous byproducts that require venting to prevent inhalation. The flue helps release smoke and air toxins out of the house safely, but improper sealing can result in carbon monoxide and other gases seeping into the home. Sealing the flue pipes keeps the furnace running safely.

Things You'll Need

• Metal foil tape
• Aluminum flashing
• Construction staples
• Heat-resistant silicone caulking

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Instructions

1. • 1

     Check the joints of the flue pipes to verify they are secured by three sheet metal screws. Wrap metal foil tape around the joints to further prevent escaping air.

   • 2

     Wrap aluminum flashing around the flue pipe. Secure it to itself with construction staples. Do not puncture the flue pipe itself.

   • 3

     Apply heat-resistant silicone caulking to the seam where the edge of the flashing meets the flue pipe. Allow it to dry.