Do This With Your Furnace In October & Thank Yourself All Winter Long

Finally, the temperatures are dropping and it's starting to feel like fall. But don't relax just yet. The checklist to prepare your home for winter is long, with jobs inside and outside the house. And one very important task is changing your furnace filter. Sure, you need to change the filter year-round at regular intervals (which varies based on the type of filter and the conditions inside your home). But October is a particularly prime time for the task since you're heading into the heating season.

There's a lot you need to know about furnace filters, including the right timing and why having a clean furnace filter is important. You might assume the biggest issue if you don't change the filter in October is dirty air circulating through your home. And, yes, that's a problem when it comes to indoor air quality — especially when you'll have the house closed up for the winter and all that dirt will keep circulating. But it's not the only issue. A clogged filter makes your furnace work harder, which can lead to overheating and premature wear on crucial components. If it stays that way, you could end up with high-cost repairs.

October is the month when you may need to start using your furnace. In many areas, once you turn the furnace on, it's running until spring — it's common for households to use the furnace for at least six months out of the year. You don't want to go into that long stretch of furnace operation with an already dirty furnace filter. If you do, your furnace might not last the winter as it shows signs of a struggle.

Knowing when and how to change your furnace filter is essential for keeping everything running as expected. It's a good idea to set your furnace up for success in October before the truly cold temperatures set in. That often includes a professional tune-up to check for potential safety and operation issues, but it should definitely include a filter swap, too. During the summer, it's possible for dust and debris to settle in your HVAC system instead of getting removed by the filter. The warm air and frequent operation of your furnace often send that settled debris through the system, so putting a new filter in helps keep up with that dust.

If you last changed the air filter at the beginning of the summer, you'll definitely want to change it now in October. If you replaced it more recently, inspect the filter carefully. It's a good idea to swap it if it's dirty at all, even if you would normally let it go longer. That way, your system can go for several weeks without any excess strain or reduce airflow.

Are pricier furnace filters actually worth buying when you change it in the fall? That depends on your budget and personal needs. What's important is simply getting a clean, fresh filter in the unit before the intense heating season starts. No matter which type of filter you choose, check it every four to six weeks throughout the heating season, just to see if it's getting dirty and needs to be changed again. The constant use of a furnace often means the air filter gets dirty faster in the winter, so staying on top of it prevents excess wear.