A safely heated home doesn’t happen by mistake. A home’s furnace requires maintenance and attention. That’s why homeowners need to have a solid maintenance checklist in mind to help their homes stay safe and comfortable season after season. Yes, maintenance and checkups need to be done every year. Make it sooner if you notice anything that seems off. Yes, maintenance and checkups are still necessary even if you have a new furnace. A furnace that looked great last year may have a new problem that is putting you at risk for a big surprise this year.

It’s important not to think of furnace maintenance as a hassle. Keeping your furnace properly maintained has many benefits. Here’s a look at some of them:

  • Better Efficiency: Keeping your furnace properly maintained can ultimately help you to avoid unnecessary heating costs stemming from a broken or inefficient system.
  • Safety: Keeping your furnace properly maintained can help to prevent dangerous fires caused by blockages or debris.
  • Damage Protection: Routine furnace maintenance can protect you against pricey repairs by preventing issues with your furnace. In addition, an issue that’s caught early might be fixable before it becomes an expensive problem.
  • Longevity: Having your furnace serviced is one of the best ways to expand its lifespan! Think of what you’d rather be spending that money on!

What should be included on your annual furnace maintenance checklist? While systems differ, the general rules regarding what needs to be covered are pretty universal. Here’s a look at the items to include on your maintenance checklist.

Start Outside

When was the last time you walked around your property to take a peek at how your system looks from the outside? Do a walk around your home to ensure that your vent and exterior heat pump look good. Make sure that no debris, vegetation, or other things are crowding the area. You want several feet of open space to ensure proper airflow.

Air Filters

Checking your air filters is essential. However, this isn’t just something that needs to be done during your annual furnace checkup. Air filters should be changed roughly every three months. The mileage you get out of each filter will vary based on things like your usage, the size of your home, and how much air pollution your home tends to have. However, it’s a good idea to check filters monthly to get a status update even if you only need to change your particular filter every three to six months.

A clean air filter isn’t just essential for your furnace’s performance. It’s also essential for keeping your home safe for both humans and pets. Clean filters reduce contaminant levels in your home’s air. A clean filter also ensures proper airflow without restrictions. A clogged filter will allow pet dander, pollen, dust, and mold to linger in your home.

Floor Vents

Many homeowners ignore their floor vents. However, this is a big mistake because floor vents attract dust, debris, dirt, pet fur, and human hair. They can even collect food particles from your home that can attract critters. Make sure they’re being cleaned!

When your vents are clogged with “junk” from your home, they cannot work as efficiently as they should. Yes, a simply clogged vent can drastically reduce your furnace’s efficiency. That means many homeowners are actually wasting money by needlessly cranking up the heat just because everyday clutter has found its way into their vents.
Of course, there’s also the danger of air pollution caused by allowing particles to linger in your vents.

Insulation and Ducts

Getting into the “bones” of your home’s furnace system is also important. Having a pro take a look at your insulation to let you know if poor insulation is forcing your heating system to work overtime can be essential for making your home’s heating system more efficient. You should also have your ducts looked at to see if there’s a problem there. It’s quite common for poor ductwork to cause homeowners to lose heat from their homes. Some common concerns to check for when inspecting your ductwork include dust, corrosion, mold, rust, and opened joists.

Controls and Safeties

Don’t forget about testing controls and safeties to verify that they are in working order. These features have built-in triggers that prevent things like overload and malfunction. Controls often contain error notices that can help you quickly diagnose a problem.


Your furnace’s thermostat is just waiting to reveal important details about the health of your system. Have you been paying attention to how your thermostat acts? If a thermostat is shutting off within a few minutes of turning on, you likely have a cycling issue that’s going to require recalibration or replacement. It’s also important to ensure that the thermostat is performing accurately.


If your home uses hot water for its heating system, you should definitely check to make sure that your thermostat and piping are in sync. It’s important to crank your thermostat to allow pressure to build up when doing a simple check. Next, get down to the boiler area to ensure that pipes and valves aren’t producing leaks.

Combustion Chamber and Blower

Your furnace’s combustion chamber is the space where fuel and air mix to create an ignition that generates heat. Unfortunately, this function can make the combustion chamber a prime spot for soot buildup. The biggest sign that you have a chronic soot issue is the presence of corrosion. It’s essential to brush away any soot to prevent this problem from happening.

Blower Belt

The blower belt should also be inspected. What don’t you want to see when inspecting your blower belt? Any sign of wear and tear can mean that the belt is compromised. A compromised belt is a slow, inefficient belt. You also want to look for proper tension levels.


It never hurts to check if panels need to be tightened or adjusted. A jostled panel can actually be enough to reduce your furnace’s efficiency. The telltale sign that you have a jostled panel is a rattling sound. In addition to wasting energy, a simple loose panel can actually put your household at risk for carbon monoxide exposure.

Oil Filters

If you have an oil furnace or boiler, it’s so important to change out your oil filter with one that’s the same model once a year. While your filter is being changed, it’s a good idea to take a close look at the nozzle. It’s very common for oil nozzles to become clogged with fuel impurities that can cause a lag in performance. It’s also important to make sure that an oil filter is being disposed of properly after every change!

Flue Pipe

Checking your furnace’s flue pipe is essential for preventing carbon monoxide leaks! You’re looking for holes and cracks in the exhaust pipe that can allow carbon monoxide to spill through when doing this portion of the inspection. Don’t assume that any hole you see can be patched up. You will need to replace any broken or corroded flues for the safety of your household.

Drains and Traps

Furnace drains and traps should be checked for leaks. You’re usually looking for at least two internal drains per unit. When there’s any type of accumulation, you’re at risk for a combustion malfunction. Leaks and cracks are telltale signs that something has already gone wrong with your drain line.

Making a Plan for Furnace Maintenance

This list doesn’t come anywhere near covering all that goes into a complete furnace inspection. A full inspection mixes visual assessments with actual diagnostic testing using specialized tools. Some of the high-level aspects of a furnace check include:

  • Static air pressure test.
  • Temperature rise assessment.
  • Gas pressure test.
  • Combustion gas test.

Homeowners don’t have to feel like they need to figure this out all on their own. In fact, trying to do your own yearly furnace maintenance can actually be dangerous. You also risk damaging your furnace in the process. The U.S. Consumer Product Safety Commission (CPSC) has recommended for decades that a qualified heating contractor should inspect every home heating system annually. That’s why your neighbors simply call Delaware Heating and Air Conditioning when they need their furnaces checked. We provide full-service furnace maintenance that will give you peace of mind. Book a furnace checkup with us today!