Furnace Maintenance Checklist: Keep Your System Running All Season Long

Modern HVAC September 12, 2025 0 Comment

As the winter season approaches, your furnace will be the focal point of keeping your home warm. Our comprehensive furnace maintenance checklist below will help inform you of what you need to know to keep your unit running all throughout Wisconsin’s cold winter season.

We’ve broken down our tips into monthly, seasonal, and yearly maintenance tasks. Let’s go over each below to help you know how to prepare your furnace for winter:

Monthly Maintenance Tasks

Furnace Short Cycling - Clean Air Filter

Clean or Replace Air Filters

The most important monthly task is replacing or cleaning your air filters. Clogged filters are one of the leading causes of furnace problems we encounter in our service calls throughout Appleton, Neenah, and the surrounding Fox Valley communities.

Dirty filters restrict airflow, forcing your furnace to work harder and potentially causing expensive damage to internal components. If anyone in your home has asthma, or you have pets, you may want to consider replacing your furnace filters every 4-8 weeks.

Check Thermostat Settings

Before late fall sets in, it’s a good idea to take a look at your thermostat. We suggest checking your thermostat settings monthly and replacing the battery (if it’s battery-powered). Even a low battery can cause temperature fluctuations that make your home uncomfortable and waste energy.

If you need help with your thermostat, we can help! Just contact the Modern Sheet Metal team at (920) 733-4713.

Ensure Clear Vents and Registers

The last monthly furnace maintenance task we suggest performing is a walk-through of your home to ensure that all vents and registers aren’t blocked by furniture, curtains, or debris.

Blocked vents, left unaddressed, can create pressure imbalances that can put a significant strain on your entire HVAC system.

Seasonal Maintenance Tasks

Inspect Furnace Area

Before each heating season, inspect the area around your furnace. Remove any stored items, cleaning supplies, or flammable materials that may have accumulated over the summer. Your furnace needs proper clearance for safe operation and easy access for maintenance.

Listen for Unusual Noises and Check for Odors

In preparation for the season, another suggestion we have is to listen for unusual noises whenever your system first starts up. These sounds can include a grinding, squealing, or banging sound, which often indicate that one or more of your furnace components need attention before they fail completely.

Another potential issue you may experience is your furnace short-cycling, or shutting off and on. If you hear any unusual sounds or it is short-cycling, we can help.

You should also check for any unusual odors when the furnace first turns on for the season – while some dust burn-off is normal, persistent odd smells will probably requite a professional.

Test Carbon Monoxide Detectors

Don’t forget to test your carbon monoxide detectors and replace batteries. Carbon monoxide is an invisible, odorless gas that can be deadly, making working detectors essential for your family’s safety.

When in doubt, check with the indoor air quality experts at Modern HVAC for assistance if you have a question on carbon monoxide detection.

Clean Around Outdoor Units

Lastly, if you have a heat pump system, you’ll want to clean around the outdoor unit and remove any leaves or debris that have accumulated during the off-season.

Annual Professional Service

Schedule Your Tune-Up Before Heating Season

While monthly and seasonal tasks help keep your furnace running smoothly, our Carrier-certified HVAC technicians recommend scheduling your tune-up before the heating season begins, typically in early fall, to give ample time before the first snowfall.

Furnace Inspection & Cleaning

During a professional service call, our furnace technicians will inspect and clean important components of your furnace including the heat exchanger, burner assembly, and flue system.

We check all gas connections for leaks and test the electrical components to ensure safe operation. Moving parts are lubricated, electrical connections are tightened, and we test all safety controls to verify they’re functioning properly.

Testing & Troubleshooting Potential Issues

We also measure your system’s efficiency and can identify potential problems before they become costly emergency repairs. This proactive approach helps ensure your furnace operates safely and efficiently when you need it most during those cold Wisconsin winters.

Keep Your Family Comfortable All Winter Long!

Regular furnace maintenance is an investment in your family’s comfort, safety, and your home’s energy efficiency. By following this checklist and partnering with experienced professionals, you can avoid emergency breakdowns and extend your furnace’s lifespan.

Remember that preventive maintenance costs far less than emergency repairs, especially during peak heating season when service calls are in high demand.

Our Service Area

We are the furnace experts! With more than 60 years of professional industry experience serving residential and commercial customers throughout Appleton, Neenah, Menasha, Kimberly, Greenville, and Darboy, we provide HVAC solutions that you can rely on.

Our Carrier-certified technicians offer FREE estimates and second opinions to help prepare your furnace for the fall and winter months.

Contact Us for a Service

Whether you are looking for a brand new gas or electric furnace installation, have a furnace repair, or you just need a tune-up, we’ve got you covered! Our complete heating and cooling services for furnaces include installations/replacements, repairs, maintenance, and emergency services. We also handle A/C, radiant floor heating, indoor air quality, and radon testing solutions.

To get started, please contact Modern Sheet Metal today by phone at (920) 733-4713 or, contact us online!

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