Oil Furnace Cleaning

By Travis Baugh

During the cold, winter months, your furnace is the key to your comfort. Not only does it heat the air to keep you warm and cozy, but it can also provide filtering to improve indoor air quality. To keep your furnace operating reliably and efficiently, it’s important to make sure it is maintained serviced on a regular schedule. Oil furnace cleaning, whether you are a “DIYer” or a “call the professional” type, should be done annually as a part of a standard furnace service routine.

When comparing types of furnaces , oil furnace maintenance is a little more involved than an electric or natural gas furnace. That is due, in part, to the oil filter which will need to be replaced on a scheduled basis. While a number of the steps are fairly simple, furnace cleaning is not for everyone. Considering the time and effort involved, we recommend calling a professional experienced in furnace repair and service. Your local Carrier expert, for example, will have the tools, knowledge and background to service your oil furnace efficiently. In the long run, a well-maintained heating system will operate more efficiently and save you money on fuel.

How Often Should You Have Your Oil Furnace Cleaned?

How often should you have your oil furnace cleaned? To maintain your oil furnace and keep it running efficiently, we recommend yearly furnace maintenance from a trained HVAC professional. As grime and carbon soot build up over time, it makes your furnace work harder, causing strain on components and increasing your energy costs. At a minimum, it should be cleaned at the beginning of each heating season, but repeating the process mid-year will help keep your furnace in peak condition and help prevent future problems.

Oil Furnace Cleaning Tools

Not all furnaces are exactly alike, but oil furnace cleaning tools that will likely be needed for most models may include:

Screwdriver
Nut driver
Wire brush
Rag
Strap wrench
Shop vac or commercial-grade vacuum

How to Clean Your Oil Furnace

While some of the tasks involved are relatively simple for most people, we recommend contacting a Carrier expert to clean your oil furnace. When you call a local Carrier expert, you can expect a full, professional cleaning and inspection with a trained eye. While every technician may have a slightly different checklist of items to clean or service, here is a step-by-step look at how to clean your oil furnace.

Step 1 - Turn Off Power and Fuel Supply

The first step is to operate safely by turning off the power and oil supply to the furnace. The power switch on your furnace usually looks like a standard light switch. Most oil tanks include a fuel shutoff valve near the bottom of the tank.

Step 2 - Clean the Combustion Chamber

The combustion chamber on oil furnaces can experience a buildup of carbon soot which can cause corrosion or material degradation of the chamber walls. Your dealer will likely use a stiff wire brush to loosen the soot build-up and vacuum the inside of the chamber.

Step 3 - Clean the Heat Exchanger

Well-tuned oil furnaces should not require annual heat exchanger cleaning. If necessary, the interior of an oil furnace heat exchanger can be cleaned using compressed air and a commercial-grade vacuum.

Step 4 - Check the Flue Pipe

The exhaust flue should be closely examined for corrosion, holes, or a poorly sealed connection to the furnace itself – a likely location for leaks. Small openings in the flue can be repaired with foil tape, but larger issues may require replacing the flue pipe.

Step 5 - Replace the Oil Filter

To keep the oil burner from clogging, your furnace includes an oil filter that removes impurities from the fuel oil. To replace the oil filter, your technician will remove the old filter with a strap wrench or specialized filter wrench, and install a new compatible filter.

Step 6 - Replace the Air Filter

If you haven’t done so already, your HVAC pro will inspect, and if needed, replace the furnace air filter. The filter should be replaced every 30 – 90 days to prevent buildup of dust and debris that can restrict airflow and affect furnace performance. Keeping the filter properly maintained can also improve indoor air quality.

Oil Furnace Cleaning Service

Ignoring your home heating system may not lead to catastrophic failure right away. However, allowing dust, dirt and soot to buildup on critical components can lead to loss of efficiency, loss of comfort, and undue wear and tear on the equipment. That’s why we recommend an oil furnace cleaning service at least once annually by a trusted HVAC professional.

You can find a Carrier dealer in your area using our dealer locator. Your local Carrier expert can clean your oil furnace, make any minor repairs as needed, and make additional recommendations for the health of your system.

Frequently Asked Questions About Oil Furnace Cleaning

Can I clean my oil furnace myself?

You can perform basic maintenance on your oil furnace, such as replacing or cleaning the air filter and dusting external components. However, cleaning internal parts like the burner, heat exchanger, and flue pipe is best left to a professional due to the complexity and safety risks involved. Proper cleaning requires specialized tools and knowledge to ensure safe and efficient operation, so scheduling an annual professional tune-up is recommended for thorough maintenance.

How often should an oil furnace be cleaned?

An oil furnace should be professionally cleaned once a year to maintain optimal performance and safety. Annual cleaning helps remove soot, dirt, and debris from key components like the burner, heat exchanger, and flue, ensuring efficient operation.

How do you clean the combustion chamber on an oil furnace?

It's recommended to have a professional perform combustion chamber cleaning of an oil furnace to ensure safety and thoroughness. They will turn off the power and fuel, remove the access panel, use a long-handled wire brush to scrape off soot and carbon buildup from the chamber walls, use a vacuum with a hose attachment to remove loose debris and soot, replace the access panel, and then restore power and test the furnace.

What happens if you don't clean your oil furnace?

If you don't clean your oil furnace, soot and debris can build up, reducing efficiency and increasing energy costs. Over time, this can lead to clogs, poor combustion, and potential system failures, resulting in costly repairs. Dirty furnaces also pose safety risks, including the potential for carbon monoxide leaks and fire hazards.

Do I have to bleed my oil furnace?

The process involves turning off the furnace, locating the bleed valve, placing a container underneath, and loosening the valve while running the furnace to let air escape. Once fuel flows steadily without air bubbles, close the valve. However, if you're unsure or unfamiliar with the process, it’s safer to have a professional handle it to avoid potential fuel leaks or system damage.

Learn More About Oil Furnaces

Browse Carrier oil furnaces
How do oil furnaces work?
Learn about the cost to replace an oil furnace