How to Catch Soot From an Oil Furnace Stack

Turn off the power to the oil furnace before cleaning the chimney. Locate the outdoor exhaust vent leading from the chimney. Climb up on a ladder and remove the chimney cap from the vent. You may need to unscrew the cap.

Clean your chimney with the chimney brush, the size of which depends on the size of the flue. Snap an extension pole onto the end of the chimney brush, turning the pole clockwise to tighten it. Push the brush down into the chimney. Attach another pole to the first pole and push the brush down further. Keep pushing the pole down and adding extensions until the brush is at the bottom of the chimney and you've used all the poles.

Scrub the chimney by pushing the brush down and pulling it up. Periodically remove the brush from the chimney and check the chimney with a flashlight for soot. Keep scrubbing until the chimney is empty of soot.

Open the door on the bottom of the chimney and vacuum any soot caught inside it, using the shop vac.

Climb back onto the roof and replace the chimney cap on the exhaust vent. Vacuum the exhaust stack damper opening.