How to Clean and Clear Furnace Exhaust Vents. Gas and oil furnace have a vent pipe or flue that sends the gaseous by-products of combustion to the outdoors. Depending on the type of furnace, venting takes place through a plastic pipe on the outside of the house or through the chimney. Over time, the furnace exhaust vent can become clogged with debris.
Locate the exhaust vent on the exterior of your home.
Check for ice and snow during the winter, especially after severe or heavy storms.
Keep the vents clear of debris. Remove nests, clear out the leaves during autumn or after a heavy wind, and sweep or vacuum out dirt that accumulates in the vent.
Cut away any shrubbery, trees, branches and vines that may impede the function of the furnace exhaust vent.
Clear or replace the filters regularly. Keeping the filters clean will maintain maximum airflow and help keep debris from building up in the furnace exhaust vent. Do this approximately every three months, or even more frequently in a new home or a home with pets.