How to Clean a Furnace Vent Pipe

eHow may earn compensation through affiliate links in this story.

Things You'll Need

  • Handheld, battery-powered vacuum

  • Gloves

  • Work clothes

  • Screwdriver

  • Protective eye wear

  • Hedge clippers

  • Scissors

  • Cleaning rags

  • Scrubbing dust brush

  • Ladder

  • Long hook

Furnace heating systems are an important part of keeping a home comfortable during the winter months, but because they filter air and use a combustion process to make heat, they get dirty and need to be cleaned every few months. Most people know about cleaning and changing the filter, but equally important are the furnace's vent pipes that carry away the gases produced during the combustion process outside of the home. Cleaning the vent pipes is a simple process and should require no more than a few hours of your time.


Step 1

Read your furnace's owner's manual to see if there are any specific cleaning practices for your model or if certain actions will void your warranty or are considered unsafe. Make note of any precautions you should take and, if nervous, consult a certified maintenance technician. Before beginning, turn the furnace off.

Video of the Day

Step 2

Locate your furnace vent pipe. Typically seen coming out of the roof, they are long and tubes of piping that may be white or gray in color and should have a circular cap over their top. Use a ladder to access your roof and have someone help you bring your tools up if necessary.


Step 3

Put on your gloves, eye wear, and any other dust protection and use the screwdriver to remove the vent cap. Once open, you should be able to see inside the vent. There may be evidence of bird nests, ice, dust, or natural debris, which get caught in the pipes over time. Remove what you can with your hand and utilize a wire or plastic hook to reach any of the debris that may be farther down and blocking the pipe.

Step 4

Scrub the inside free of any dust and debris; then use the handheld vacuum to get out as much as you can. Wipe it clear with a rag or soft cloth and then replace the cap. Cut away any branches or remove any object that might be obstructing the pipe and creating debris. The vent should always be clear.


This is a good time to clean or change your furnace filter as dust and debris that falls back down the pipes as you clean may end up there. Also, having a completely clean system, will allow it to run more efficiently and safely.


If you smell gas or burning, immediately turn off the system and contact a technician. There may be a blockage you cannot reach that can damage the system or cause personal injury.

Combustion in gas furnaces produces some carbon monoxide, which is a toxic gas. Most of the time this gas escapes through the vent pipes but if the pipe and furnace are not properly maintained the gas may not be dispelled. It is colorless and odorless, and produces symptoms similar to the flu.