How to Clean an Oil Furnace

Man repairing a furnace
  • 2-4 hours
  • Beginner
  • 0-1,000
What You'll Need
Adjustable wrench

Cleaning your oil furnace is extremely important since oil is a very dirty type of fuel that gets gritty over time. In order for your oil furnace to run efficiently, it should be cleaned before the winter season comes so that it can function well, and need to be cleaned every month during continuous use throughout the cold season. If your oil furnace gets too difficult to clean, the furnace filter should be replaced with a new one.

Step 1 - Turn off Power

Always remember that when working on home appliances that turning off the main power source is very important. Working on an appliance that is currently powered can cause electrical accidents and burns.

Step 2 - Remove Panel Covering

man repairing a furnace

The furnace is often covered with a metal panel. Using your screwdriver, remove the panel to be able to access parts of the oil furnace to be cleaned.

Step 3 - Slide off Filter

Look at your filter and evaluate the amount of dirt on it. If it is extremely clogged, it is better to replace it than to have it cleaned. If you need to replace the filter, take the old filter to your local hardware store and get a replacement. Some oil furnaces can have a permanent filter attached to it. It is best to check your owner’s manual on how to go about cleaning your filter.

Step 4 - Remove Fan Unit

If this is possible, use your wrench and screwdriver to loosen the screws and bolts that attach it to the furnace. Use your vacuum cleaner to remove all the dirt and debris that has collected in your furnace. For the tougher dirt that has collected on the surfaces, use a brush and gently brush away stubborn dirt. Use your vacuum again to remove the debris that has loosened from the surfaces. Make sure no dirt is left inside the furnace after you have cleaned it.

Step 5 - Clean Fan Blade

man inspecting a furnace system

Fan blades collect a lot of dirt and debris, too, so they require cleaning as well. Gently brush the blades and if possible, soak them in soapy water to loosen the dirt. Once cleaned, dry with a rag. Use your vacuum if any more stubborn dirt is left hanging on the blade. Check the corners and edges as well to ensure they are clean.

Step 6 - Replace Filter and Fan

Put back the fan and secure the bolts and screws that hold it in place. Slide the cleaned or new replacement filter into place. Once the filter and fan are in place, screw back the metal panel cover of your furnace.

Step 7 - Turn on Power Source

Check if you have properly replaced the fan and observe if the furnace is working better.