Fire up for a comfy winter
Making sure your furnace is well-tuned prevents breakdowns, costly repairs, and high utility bills. This means your holiday season will be comfy, cozy, and relaxing—just as it should be. Follow these 16 furnace maintenance tips to keep your furnace in peak condition all winter and extend its life span.
One of the most straightforward furnace maintenance tips that can extend the life of your furnace is cleaning or replacing your air filter. Clogged air filters restrict airflow and heat flow, making your furnace work harder than it needs to.
Install the same size and filter type as the one you replace, and set a calendar reminder to change your filter once every three months. Some furnaces have permanent filters that you can clean. Vacuum the dust and debris from a permanent filter with a shop vac. Rinse the filter with water, then let it air dry before placing it back in your furnace.
You'll see a flame in the combustion chamber if you have an older gas furnace (most models built before 2010). The flame should be a consistent blue flame. You likely have dirty burners if the flame is a color other than blue or if it’s uneven. You'll need a certified HVAC pro to fix the issue.
Newer furnace models use electricity to ignite the furnace, so you won't see the flame or need to deal with it.
Make sure all of your vents are open and unobstructed. Even if you have unused rooms, keeping the vents open and clear is essential. Blocked and closed vents can cause duct leaks and excessive air pressure in your HVAC system, leading to more issues and damage.
Clean your vents by removing the vent covers and vacuuming out debris, dust, and hair with a shop vac. Place the end of the vacuum hose into the ductwork to clean out dust and debris. You may want to schedule a professional duct cleaning, which costs $380 on average, if you live in a home with lots of pet hair or dust. If you spot anything inside your exhaust pipe, a local furnace maintenance professional can clear it out to make your system safer and more efficient.
Natural gas and propane furnaces have drainage pipes that move moisture away from the unit to keep it dry and mildew-free. Cleaning the pipes ensures the tube doesn't get clogged with sediment or mildew.
Turn off the power to your furnace at the electrical panel before starting. Find the end of the condensate line, often located on the outside of the unit leading to the drip pan. Look at the end of the line for blockages and debris. Clear away obstructions or buildup with a small brush, or suck the debris out with a shop vac.
If you suspect sediment buildup, pour 1 cup of vinegar down the drain tube at the T-joint. Let the solution sit for 20 minutes, then flush it with water.
Turn off your furnace at the breaker panel before cleaning the unit. Vacuum the exterior of your furnace with a shop vac to remove dust, hair, and debris buildup. Make sure the floor space around the furnace is also clean.
Store all items at least 30 inches from your furnace to allow for ample airflow for the furnace’s combustion. It’s especially important to keep toxic chemicals and flammable objects away from the furnace, including paint, fuel, and household cleaners.
With the power switched off at the breaker, open the access panel of your furnace to clean inside, specifically the blower blades, fan, and burners. Use a shop vac with an extension hose to remove all dust and debris. Use an old toothbrush to remove any remaining debris from the blower blades. You may need to remove the blower from the furnace before cleaning it.
Be gentle when cleaning the blades. You don't want to harm the wiring or counterweights. If you don’t feel comfortable cleaning with a sensitive touch, leave the interior furnace cleaning to the pros because internal damage can be costly to repair.
The flame sensor is an integral part of your furnace, and it can get coated with residue over time and prevent your furnace from lighting. With the furnace’s power off, pull the flame sensor out of its bracket and use a cleaning cloth to remove dirt and debris. Place the sensor back in its bracket.
Some old furnace models have two motor bearings and two blower shaft bearings that need oiling once a year. With the power to the furnace off, remove the oil caps and apply three drops of lightweight machine oil. Put the caps back on.
Your outdoor heat pump unit needs proper airflow. Turn off the breaker to the HVAC unit on your electrical panel. Make sure the outdoor unit is clear of debris, bushes, and other vegetation. Remove any leaves and debris with work gloves. Trim shrubs and trees to be at least 2 feet from the unit.
Your combustion flue, also called the exhaust, allows gas to exit your home. Ensure that the flue is clean and clear of leaves, animal homes, and other debris. Most flues are located on your roof, but some are on a side wall or above the garage. Climbing on a roof is always dangerous, no matter the circumstances. Call an HVAC professional to inspect and clean your flue, especially if it’s on the roof.
If your thermostat uses batteries, pop in a fresh set of batteries to ensure your thermostat doesn't stop working at a critical time in the middle of winter. Have an extra set of batteries on hand.
Make sure your thermostat’s settings work for your schedule. You may want to keep the house cooler while you're gone at work or ensure a warm temp in the morning when your family is getting ready for work and school. A preprogrammed thermostat can save energy and lower your utility bills.
When you're on vacation in the winter, set your thermostat to a minimum of 55 degrees Fahrenheit to save on utility costs and ensure your pipes don't freeze.
You should have carbon monoxide detectors on every floor in your home and, ideally, in or just outside of each bedroom. Run a test to make sure they are working before the winter starts. Change the batteries to new ones at least once a year. If you have a natural gas furnace, the danger of carbon monoxide poisoning is higher in winter, so it’s essential that your detectors are working and have reliable batteries.
Install carbon monoxide alarms on every level of your home, in central locations, and outside bedrooms. Check all of your carbon monoxide detectors every month, and replace the batteries on a set schedule according to the manufacturer’s instructions.
The first time you turn on your furnace for the season, debris and dirt may get kicked into the air through the ductwork. Turn on your furnace and have it run for an hour with the windows open so that the dust leaves your home.
The test also allows you to check for furnace problems. If you smell burning rubber or plastic, you might have a foreign object in your heater. Bring in an HVAC expert to avoid inhaling burnt plastic fumes.
Keep an ear out for strange noises as you fire up your furnace for the first time and throughout the winter. Banging, scraping, screeching, or slapping sounds can signal electrical and mechanical problems in your furnace. If you hear these noises, call a local furnace maintenance company right away.
If your furnace and AC share the same ductwork, your ducts may have dampers that require you to switch them for the season. You should see the season settings marked on your ductwork near your furnace. Two-story houses often have two separate supply trunks. Adjust the damper handle on each supply trunk to send warm air downstairs in the winter and cold air upstairs in the summer.
Go to your basement (or wherever your HVAC supply trunks are) and look for gaps and cracks in the ductwork that might leak air. Use metal HVAC tape or aluminum-colored silicone caulk to seal the gaps. Reinforce any joints that have gaps. Sealing the gaps prevents air leakage and ensures a more efficient heating system. It also helps save on monthly energy costs.
Tackling furnace maintenance once a year is critical to ensure the safety and efficiency of your HVAC system. If you don't feel comfortable performing the maintenance, or you have an older unit that needs extra care, schedule a furnace inspection and service with a local HVAC pro.
If you notice a foul, rotten egg smell coming from your furnace, you may have a gas leak, which can be lethal. If you suspect a gas leak, leave your house immediately, call 911, and contact an emergency HVAC professional.
"Getting a tuneup before cold weather hits ensures you don’t find yourself without heating when the temperatures drop."
— Randy Boutte, HVAC Technician Training Manager, HomeServe USA, Norwalk, CT
You can maintain your furnace in several ways, including replacing your air filters, checking your exhaust pipe, noting any abnormal smells or sounds, and keeping your vents clean. However, you should still have an expert inspect your furnace every year to ensure it works well and prevents expensive problems.
Without proper cleaning and maintenance, your furnace will collect dirt, dust, hair, and other debris—all of which can go into your ductwork and re-circulate into your house. As a result, you might find breathing harder, especially if you have allergies. Dirty furnaces also need more energy, so your utility costs could increase if you don’t clean your furnace. In severe cases, a lack of maintenance can cause your furnace to break down.
Although many companies offer professional air duct cleaning, the Environmental Protection Agency (EPA) says you should only consider cleaning your ductwork in a few circumstances. If you have “substantial visible mold growth,” for example, you might benefit from duct cleaning. The same applies to a vermin infestation or excessive dust and debris in your ducts.
