Why Should You Change Your Furnace Filter in the Fall?
In most Southern California homes, the filter that serves your furnace is the same one that spent the summer working behind your air conditioner. It’s been catching dust, pollen, and pet hair since spring, and in some neighborhoods it’s caught wildfire smoke and Santa Ana dust on top of that. Before the first cool night sends your furnace into regular use, it’s a smart time to change your furnace filter.
A fresh filter is one of the cheapest and easiest things you can do for your heating system. It helps your furnace breathe, keeps parts from running hot, and cleans the air your family breathes all winter.
Adeedo has served Southern California homeowners since 1949. Here’s why a fall filter swap matters, how to pick the right filter, and how to change it yourself in a few minutes.
Why Should You Change Your Furnace Filter in the Fall?
Change your furnace filter in the fall because it has likely been loaded up by a full summer of air conditioning, and a clogged filter restricts the airflow your furnace needs to run safely. A clean filter at the start of heating season protects your equipment and your indoor air.
- Do My AC and Furnace Share the Same Filter? In most homes with central heating and air, yes. The same blower moves air for both systems, so one filter handles both. If your AC ran hard all summer, that filter is probably due.
- Can Santa Ana Winds Clog My Filter Faster? They can. Fall winds carry dust and dry debris, and they often arrive during fire season, when smoke can drift in from far away. Every bit of that air that gets indoors passes through your filter, which fills faster than it would during a calm month.
- What Happens If I Run My Furnace With a Dirty Filter? A clogged filter chokes off airflow, and the heat exchanger can overheat. When that happens, a safety switch shuts the burners off, and the furnace cycles on and off without warming the house. Over time, that strain wears out the blower motor and other parts sooner than it should.
- Does a Dirty Filter Affect Indoor Air Quality? Yes. Once a filter is loaded, it captures less and can let built-up dust pass into your ducts. With windows closed more often in cooler weather, the air inside your home recirculates through that filter all day.
How Often Should You Change Your Furnace Filter?
Check your furnace filter every month and replace it whenever it looks gray or dusty. Many standard 1-inch filters need changing every few months, and homes with pets, allergies, recent construction, or nearby wildfire smoke often need changes more often. Thicker media filters usually last longer, so follow the manufacturer’s guidance printed on the frame.
Which Furnace Filter Should You Use?
The right furnace filter fits your system exactly and has a MERV rating your equipment can handle. MERV, short for Minimum Efficiency Reporting Value, tells you how well a filter captures small particles. A higher number captures more.
- Match the Size Exactly: The size is printed on the edge of your current filter, such as 16x25x1. A filter that’s even slightly too small lets air slip around the edges, so it isn’t filtering much at all.
- Choose a MERV Rating That Fits Your Home: A mid-range pleated filter works well for most households. Higher ratings catch finer particles, but they also resist airflow more, so not every system can use them.
- Plan Ahead for Smoke Season: The EPA recommends a MERV 13 or higher filter during smoky periods, provided your system can accommodate it and the filter gets changed often. If you’re not sure whether your furnace can handle that rating, our technicians will check it during your next visit.
- Keep a Spare on Hand: Filters sell out quickly when air quality alerts hit. Buying two or three at a time means you’ll have the right size ready when you need it.
How Do You Change Your Furnace Filter?
Changing your furnace filter takes about five minutes and no tools in most homes.
- Turn the system off at the thermostat
- Find the filter at a return grille in a hallway wall or ceiling, or in a slot at the furnace in your attic, garage, or closet
- Slide out the old filter and note the size and the airflow arrow
- Insert the new filter with the arrow pointing toward the furnace
- Close the grille or panel so it seals fully
- Write the date on the filter frame
- Turn the system back on and confirm air is flowing from your vents
If your filter sits in an attic furnace that’s hard to reach safely, our technicians will swap it during a tune-up.
When Is a New Filter Not Enough?
A new filter won’t fix a furnace that short cycles, blows cool air, makes new noises, or gives off a smell that lingers past the first few minutes. Those signs point to a problem a technician should check. A fall furnace tune-up from Adeedo will cover the burners, ignition, safety controls, and airflow, along with the filter itself.
CHAMP Rewards, our maintenance plan, keeps your heating and cooling tune-ups on schedule every year. For more warning signs to watch for, read our guide on whether your furnace is winter-ready.
Start the Season With a Clean Filter
A fall filter swap takes a few minutes and helps your furnace start the heating season with the airflow it needs. If you’d like a technician to handle it along with a full tune-up, we’re ready to help.
Adeedo’s courteous, skilled technicians provide up-front pricing and back every job with our 100% Happiness Guarantee. Call (833) 936-1791 or schedule online, with day and night service available, including weekends and holidays.
We proudly serve Los Angeles, Burbank, Glendale, Pasadena, Santa Monica, Culver City, West Hollywood, Inglewood, Torrance, Redondo Beach, Manhattan Beach, Long Beach, and communities throughout Southern California.