The first freezing night of the year isn't the ideal time to discover that your furnace isn't working properly.

Before we settle into another cold winter, take time this fall to make sure your home's heating system is prepared for the months ahead.

ENERGY STAR recommends annual pre-season HVAC checkups, with heating-system maintenance ideally taking place in the fall before contractors become busy during the winter heating season.

Here's where to start.

Check Your Furnace Filter

A dirty filter restricts airflow and can cause your heating system to work harder than necessary.

ENERGY STAR recommends inspecting, cleaning or changing HVAC filters monthly. A dirty filter can increase energy costs and may contribute to premature equipment failure.

Before heating season begins, check your filter and replace or clean it when needed according to your system manufacturer's recommendations.

Test Your Thermostat

Don't wait until the first cold morning.

Switch your thermostat to the heating setting and make sure the furnace responds appropriately. Listen during startup and confirm that warm air eventually reaches the home's supply vents.

It's also a good time to review programmed heating schedules and replace thermostat batteries if necessary.

Clear Your Vents and Furnace Area

Take a quick walk around the house to make sure furniture, rugs, curtains or other belongings aren't blocking supply vents and return grilles.

The area immediately surrounding your furnace should also remain clear. Avoid using your furnace or mechanical room as an overcrowded storage area, particularly for flammable materials.

Schedule Professional Maintenance

Some furnace maintenance isn't a DIY project.

A professional heating-system inspection can include checking electrical connections and controls, as well as inspecting gas or oil connections, burner combustion and the heat exchanger when applicable. ENERGY STAR specifically identifies these components as part of heating-system maintenance.

Scheduling that appointment in the fall gives you time to address potential problems before your heating system is working its hardest.

Test Your Carbon Monoxide Alarms

If your home has fuel-burning heating equipment, carbon monoxide safety deserves special attention.

Use your fall furnace-preparation routine as another reminder to test the carbon monoxide alarms throughout your home and make sure they haven't reached their manufacturer's replacement date.

Don't Wait for the First Cold Snap

Your furnace plays an important role in keeping your home comfortable and safe throughout the winter.

Check the filter, test the thermostat, clear vents and schedule preventative maintenance before you truly need the heat.

A little preparation this fall can help you head into winter with greater peace of mind.