How to Clean an Oil Furnace: 10 Tips for Optimal Performance

Homeowners in New England rely on oil furnaces to keep them warm during the frigid winter season. Since it has more moving parts than an electric or gas furnace — especially the oil filter — keeping an oil furnace clean is critical to ensure efficient operation.

While many homeowners can perform simple, routine maintenance on their oil furnaces, it’s best to have a professional cleaning from a qualified technician annually, including oil filter replacement. This article explains the steps for deep oil furnace cleaning, along with some general maintenance tips you can use for the rest of the year.

1. Shut Down and Disconnect Power to the Furnace
2. Remove and Clean the Burner Assembly
3. Remove, Inspect, and Clean the Combustion Chamber
4. Vacuum the Furnace Interior
5. Clean the Fans and Blower
6. Replace the Oil Filter
7. Replace the Air Filter
8. Reassemble the Furnace
9. Look Out for Signs of Clogging
10. Keep the Furnace Properly Ventilated

Shut Down and Disconnect Power to the Furnace

The first and possibly most important step is to cut the power and fuel supply before conducting any maintenance. Wait for the furnace to cool completely to prevent accidents and burns.

Remove and Clean the Burner Assembly

Your technician will detach the burner assembly, including all attached nozzles and electrodes. These parts are cleaned with soft cloths and mild detergent.

Remove, Inspect, and Clean the Combustion Chamber

Carbon can build up in your furnace’s combustion chamber. This can cause deterioration of the chamber walls and corrosion. Depending on the severity of the debris buildup, your technician will use either a soft brush, a stiff wire brush, a vacuum cleaner, or a combination to fully clean the combustion chamber.

Vacuum the Furnace Interior

Along with cleaning the combustion chamber, your technician will vacuum other interior fixtures of the furnace, including the chimney, flue pipe, burner area, and other surfaces. There will likely be a lot of debris and soot coming out during this step, so a mask and protective gloves are necessary.

Clean the Fans and Blower

Your technician will clean dust and debris from your furnace’s fan system and blower. This supports airflow and reduces extra strain on your heating system.

Replace the Oil Filter

This step is potentially the most crucial part of annual furnace cleaning. Your technician will remove the old oil filter and replace it with a new one. The oil filter keeps clogs out of your burner by eliminating contaminants and sediment.

Replace the Air Filter

This step should be taken every 30 to 90 days — it’s probably the easiest step for homeowners to take themselves. Changing the air filters stops the accumulation of dust, allergens, and other debris that can affect the health of you and your family. Your technician will replace the air filter during annual cleaning if you haven’t done it recently.

Reassemble the Furnace

After thoroughly cleaning the furnace, the technician will put all the components back in order, verify the job is complete, and restore power to the furnace. Following the annual cleaning, you should take a few more steps yourself over the year to ensure your furnace continues to work effectively.

Look Out for Signs of Clogging

You may not see clogging inside your furnace, but you can detect certain signs that the furnace may need cleaning. These include strange noises, unusual vibrations, lower heating efficiency, more fuel consumption, and repeated malfunctions or outages.

Keep the Furnace Properly Ventilated

Clean vents keep airflow in proper circulation and help the furnace work at peak efficiency. Turn off the HVAC system’s power and use vacuums, dusters, and cloth to remove dust and debris.

Make sure there are no other obstructions to the ventilation, like overgrown plants, furniture, pest nests, ice, or snow. This is also a good time to change the air filter.

Keep Your Furnace Running Smoothly and Safely

Annual oil furnace cleaning is key to making sure your oil furnace runs effectively for years.

While you can take certain maintenance steps like clearing vents and replacing air filters yourself, more thorough and deeper cleaning is best left to the hands of an HVAC technician. They’re best suited for cleaning the heat exchanger and burner parts, adjusting the burner flame, and checking for carbon monoxide leaks and other issues.

In addition to preventing unexpected breakdowns, proper furnace cleaning can also keep your energy and heating costs under control. Whatever time of year it is, professional oil furnace cleaning promotes solid operations, healthy conditions, and even economic benefits.

Need help with your furnace maintenance? We’d love to hear from you! Drop us a line.