--- title: "4 Crucial Furnace Cleaning and Maintenance Tasks to Complete Before Winter" description: "Careful attention to your home's HVAC system now will keep your furnace chugging away all winter long. Here are the tools you need, and what to do..." date: "2014-10-09" modified: "2021-08-13" authors: - name: "Donna Boyle Schwartz" job_title: "Contributing Writer" link: "https://www.bobvila.com/authors/donna-boyle-schwartz/" url: "https://www.bobvila.com/articles/furnace-cleaning-and-maintenance/" categories: - "DIY" - "Heating & Cooling" - "Interior" - "Repair & Maintenance" tags: - "Furnaces & Boilers" --- # 4 Crucial Furnace Cleaning and Maintenance Tasks to Complete Before Winter ![Technician looking over a gas furnace with a flashlight before cleaning it.]() *Photo: istockphoto.com* Don’t wait until temperatures plummet: Now is the absolute best time to perform basic furnace cleaning and maintenance. By tuning up your heating appliance, you can save the time and money that might have had to go into addressing a crisis, and avoid the inconvenience (and downright danger) of leaving your family without heat during the coldest part of the year. Performing these very basic furnace cleaning and maintenance tasks also can actually prolong the life of your[ furnace]() and coax it into operating at maximum energy efficiency. Follow these steps now to know how to clean a furnace and keep the unit in tip-top shape through the winter. Before you tackle any furnace cleaning, make sure to have the following equipment and materials at the ready: ### Tools & Materials Bobvila.com may earn a commission from purchases made through these links. - [Flathead screwdriver]() - [Philips head screwdriver]() - [Vacuum cleaner]() - [Cleaning cloth]() - [Foil tape]() - [Furnace filter (be sure it’s the right size for your furnace)]() - [Replacement oil filter (for oil-fueled furnaces)]() - [Lubricating oil (lightweight machine oil)]() ## Recommended Frequency of Furnace Cleaning and Maintenance The furnace is usually the only thing standing between bitter winter weather and your family’s safety and comfort, and it benefits from an annual inspection and maintenance routine. Proper care and maintenance also will help prolong the life of your furnace, and keep it running at peak efficiency. It’s recommended to clean and maintain your furnace every year, prior to the onset of cooler weather. It also is a good idea to perform a quick clean in the spring, vacuuming up any dust or soot. However, the furnace filter needs to be inspected and replaced more frequently. How often a [filter needs to be changed]() depends on the use, type of filter, and whether there are pets at home. - If you use a basic fiberglass or paper [furnace filter](), it usually needs to be replaced every 1 to 2 months during the heating season. - If you are using an electrostatic or HEPA filter, plan to change or clean it every 2 to 4 months. - If your home has multiple furry pets or smokers, you may need to change the filters more frequently to trap dust, dirt, and airborne particulates. Changing or cleaning furnace filters is perhaps the quickest and easiest way to maximize the efficiency of your heating system. Plus, a clean furnace with a fresh filter can help [freshen your indoor air](). ![Technician repairing the combi gas boiler with Screwdriver in hand]() *Photo: istockphoto.com* ## How to Clean and Maintain a Furnace Most common furnace maintenance is not complicated—you just have to have a good vacuum cleaner and some basic tools and supplies. However, there are a few precautions that are necessary before you begin. - Always turn off the electrical power and fuel supply before you start any furnace project. - Keep an assortment of tools and spare parts near your furnace – including the proper screwdrivers (regular or Philips head) to remove the door to the combustion chamber. - Keep a supply of furnace filters, a replacement oil filter, foil tape for patching small holes in the combustion chamber, flue or ductwork, and good quality machine oil for lubrication on hand. ### STEP 1: Clean out the combustion chamber. Before doing anything else, cut both the electrical power and fuel supply to the furnace. Accomplish cutting the electrical power by toggling the on-off switch on the unit. To cut off the fuel supply, first find the fuel shutoff valve. Depending on your fuel source—[oil or gas]()—the valve should either be near the oil tank or on the incoming gas pipe. Next, remove the door to the combustion chamber and proceed to vacuum the interior. Inspect the chamber for holes created by corrosion. If you find any, be sure to cover them with foil tape. ### STEP 2: Clear the blower compartment of debris. Lift off the door to the blower compartment and thoroughly vacuum inside. Just as you did in the combustion chamber, look here—and in the exhaust flue—for holes. Cover any holes with foil tape before replacing the door. Perform the same inspection on all[ ductwork](), including the return air ducts. Patch any holes. ![Man cleaning air ducts in home.]() *Photo: istockphoto.com* ### STEP 3: Clean the furnace filter. Basic furnace filters are designed to trap dust, dirt, and airborne particulates before they can enter the furnace and potentially damage its components. During the heating season, clean or [replace the furnace filter]() every 1 to 3 months (some filters can be cleaned, while others can’t). Because today’s homes are so tightly sealed, most indoor air circulates through the HVAC system. For that reason, it’s generally worthwhile to spend a bit more on a[ furnace filter]() that not only protects the appliance itself, but also enhances air quality by trapping bacteria and pollen as well as mildew and mold spores. If yours is an oil-fired furnace, remember to replace the oil filter as well as the air filter. The oil filter usually needs to be replaced annually. ### STEP 4: Oil the motor bearings. Many older furnaces have two motor bearings and two blower-shaft bearings. Both sets need to be oiled at least once per year. Start by using a clean cloth to wipe the caps over the bearings. Next, remove the caps and apply two or three drops of lightweight machine oil to each bearing, being careful not to over lubricate. Finish by restoring the caps to their original positions. ## When is it Time to Hire a Pro? Although basic furnace maintenance can be handled by most homeowners, it makes sense to hire a professional for some tasks. For example, if you’ve noticed the furnace rumbling and can’t figure out why. Any of the below situations usually call for a[ consultation with a HVAC pro](). - *Excessive soot:* If in the course of cleaning the combustion chamber you notice that an excessive amount of soot has accumulated—which usually indicates that the burners need adjustment or that the heat exchanger must be replaced—call in a pro to diagnose and fix the problem. - *Irregular flame:* The pilot light flame should be blue, not yellow. If yours is faint or irregular, it can be a sign of dirty burners or a cracked heat exchanger. Again, hire a pro to diagnose and fix the problem. The hazards involved make such work ill-advised for do-it-yourselfers. - *Short cycling:* Is your furnace running for a short period of time only to shut off suddenly? That’s known as “short cycling” and may be caused by an out-of-whack thermostat or an overheating exchanger. Retain the services of a pro to investigate and solve the problem. ![why is my furnace so loud]() *Photo: istockphoto.com* ## FAQs About Cleaning a Furnace Many people don’t really think about their furnace much until they experience [furnace problems](). As with numerous other home appliances, a little bit of regular cleaning and maintenance can go a long way towards ensuring that your furnace is running smoothly and at peak efficiency. Consider regular furnace cleaning and maintenance similar to a tune-up on your car. It’s a necessary part of your routine. Here are a few things to consider when thinking about your furnace. ## Final Thoughts Your furnace is a major investment in your home and in your family’s comfort and safety. Regular cleaning and maintenance can save you money in the long run, because it will maximize the effective lifespan of your unit. Whether you are looking to maximize the efficiency and performance of a new or existing unit, just a couple of hours of cleaning and maintenance every year will help keep your investment in tip-top shape, while at the same time it can keep you and your family comfy and cozy during the colder winter months. ## Author Donna Boyle Schwartz is an avid writer with years of experience covering the home and garden beat in addition to out-of-home topics such as sports and local events. These days, she researches and writes editorial and advertising features on a vast range of home-related topics, including housewares, furniture, home fashions, flooring, remodeling, construction, antiques, art, garden, collectibles, and color/design trends.