How to Clean Soot in an Oil Furnace

ust like wood-burning furnaces, oil furnaces can accumulate soot.

Many homes use an oil-fueled furnace to provide heat during the winter. While oil furnaces are more efficient and run cleaner than their predecessors, soot still builds up within the furnace over an extended period of time. This can not only stain and blacken the furnace, but can also reduce its burning efficiency. Cleaning the soot out of the furnace restores its cleanliness and helps it run better.

Things You'll Need

• Damp rag
• Vacuum cleaner
• Hard-bristled brush
• Dustpan

Instructions

1. Shut down the furnace if it is currently running. Wait for the heat to dissipate before touching the furnace or opening its front metal panel. Exercise caution as the outside may feel cool while temperatures inside the furnace are still hot enough to burn you.

2. Slide the oil filter out. The filter is typically inserted near the furnace's back combustion chamber and can be removed without tools. If you are unsure, consult your furnace's original manufacturer's manual. Wipe down the filter with a damp rag. If it is heavily soiled, discard and use a replacement filter.

3. Use a hard-bristled brush and brush the inside of the oil furnace, paying attention to the inside top and sides of the appliance. Use brisk up-down strokes in a scrubbing motion, brushing soot particles and debris toward the floor of the furnace. Switch hands if one arm becomes fatigued. Once the entire inside of the furnace has been brushed, scrape the refuse into a dustpan and discard.

4. Vacuum the inside of the furnace to pick up the fine, loose soot particles. Pay special attention to the corners, as you may have missed these areas while brushing. Vacuum thoroughly. Depending on the size of your furnace, this may take 30 minutes or more.

5. Wipe down the inside of the oil furnace with a damp rag. Dampen with water, and avoid using cleaners or solvents as this may create dangerous fumes or fire hazards if residues are left inside the furnace. Wiping with a damp cloth helps remove any last bits of soot and dust that may have been stuck onto the side of the furnace.

6. Replace the metal panel for the furnace and turn back on. Resume use.

Tips & Warnings

• The presence of black smoke in your chimney while running your oil furnace means the furnace isn't burning its oil fuel efficiently. This may cause significant fuel wastage. Call your furnace's service department and have a technician come to adjust your furnace.

References

• Government of Canada: Furnace Maintenance
• Troubleshooting and Repairing Major Appliances, 2nd ed.; Eric Kleinert; 2007

Resources

• Energy Star Tips for Consumer Furnaces