As the days get shorter and temperatures start to dip, your furnace is about to become the most important appliance in your home. The last thing you want is to find out it’s not working right when you need it the most.

Before the real chill sets in, take a little time to make sure your furnace is ready for fall. Here’s a practical checklist to help you prepare, avoid breakdowns, and keep your home warm and safe all season long.

1. Turn it on Early

Don’t wait for the first freezing day to test your furnace. Switch your thermostat to “heat” and set the temperature a few degrees above room temperature. The system should kick on within a minute or two.

  • If it doesn’t turn on…
  • If it smells strange…
  • Or if it makes loud banging or grinding noises…

That’s a sign you need professional service before the season starts.

2. Replace the Air Filter

One of the simplest and most important things you can do is replace your air filter.

  • A dirty filter makes your system work harder, reducing efficiency
  • It can also circulate dust and allergens through your home
  • Most filters should be changed every one to three months depending on usage and the type of filter

Pro Tip: Mark your calender to check it monthly during peak heating season.

3. Check Your Thermostat

Is your thermostat responsive and accurate? If it’s older, it may not be reading the temperature correctly.

  • Test different settings to make sure it’s triggering the furnace properly
  • Consider upgrading to a smart thermostat for better efficiency and remote control
  • Replace batteries if it’s not hardwired

A properly functioning thermostat can save energy and keep your home more comfortable.

4. Inpsect Vents and Registers

Go room to room and check:

  • Are all vents open and unobstructed?
  • Any dust buildup or debris that needs cleaning?
  • Are there cold spots in certain rooms?

Blocked or dirty vents reduce airflow, which puts stress on your furnace and creates uneven temperatures.

5. Test Your Carbon Monoxide Detectors

A furnace that burns gas or oil produces carbon monoxide, and a malfunctioning system can pose a serious safety risk.

  • Replace batteries in your carbon monoxide detector
  • Test the alarm to make sure it’s working
  • Make sure there’s a detector near all sleeping areas and your furnace

If you don’t already have detectors in place, now’s the time to install them.

6. Schedule a Professional Maintenance

Even if everything seems to be working, your furnace needs professional maintenance at least once a year.

A fall maintenance typically includes:

  • Cleaning and inspecting burners and heat exchangers
  • Checking for gas leaks or carbon monoxide issues
  • Testing the ignition system and blower motor
  • Verifying airflow and system efficiency
  • Tightening electrical connections
  • Lubricating moving parts

Pro Tip: Schedule your maintenance in early fall before HVAC companies get booked solid when the cold hits.

Bonus: Signs You Might Need a Repair

While doing your checks, look out for these red flags:

  • Unusual noises (banging, screeching, rattling)
  • Weak airflow or cold air from vents
  • A sudden spike in your utility bill
  • The furnace turns on and off frequently
  • A yellow pilot light (should be blue)

If you notice any of these, don’t wait. It’s better (and often cheaper) to catch problems early.

Stay Warm and Safe This Fall

A little furnace prep now can prevent a mid winter emergency later. Whether it’s changing a filter or booking a maintenance, taking a few simple steps in early fall keeps your system running efficiently and your home cozy when the cold hits.

At 4 Winds AC and Heating, we’re here to help you get ready for the season. Our certified technicians provide reliable, honest service with no surprises.