It’s easy to forget about your furnace filter until something goes wrong. Maybe your system is running nonstop, but your home still feels dusty. Or, maybe your energy bills are creeping up for seemingly no reason. Changing your furnace filter can sometimes address these issues.
At Allied Air Conditioning & Heating Corp., one of the most common questions we hear is, “How often should I replace my furnace filter?” The answer depends on your filter, your home, and your lifestyle. This guide covers everything you need to know (plus a few pro tips you won’t find on the packaging).
Quick Answer
Most homeowners should replace their furnace filter every 1 to 3 months. However, depending on your filter type and household factors, it could be more or less often.
Here’s a quick reference guide based on filter type:
| Filter Type | Recommended Replacement |
| 1-inch fiberglass filter | Every 30 days |
| 2–4 inch pleated filter | Every 60–90 days |
| 5-inch or HEPA filter | Every 6–12 months |
If you’re not sure what type of filter you have, pull it out and check the label or thickness. Still unsure? Give us a call. We’re happy to help you identify your filter type.
What Affects How Often You Should Replace It?
A home with pets and children will naturally accumulate more dust and dander than a quiet household of two. Homes near construction zones or with frequent visitors may also notice filters clogging faster. Seasonal usage is another factor. You will need to replace your furnace more frequently if you run your furnace a lot.
How Do You Know It’s Time to Replace It?
Extra dust around vents, weaker airflow, or worse allergies than usual may all indicate a clogged filter. One easy test is to hold the filter up to a light. If light doesn’t pass through, it’s time for a replacement.
What Type of Furnace Filter Should You Use?
Choosing the right furnace filter will affect your system performance and indoor air quality.
- Fiberglass filters are inexpensive and capture larger particles but require frequent changes—usually every month.
- Pleated filters last longer and are more effective at trapping finer particles like pollen or dust mites.
- HEPA filters offer top-tier performance, capturing up to 99% of airborne contaminants, but they aren’t compatible with all HVAC systems.
If you’re unsure which filter is right for your home and system, our team can help you choose the right size and style.
Importance of Regular Furnace Filter Replacement
Neglecting your furnace filter can lead to problems beyond decreased indoor air quality. A clogged filter forces your furnace to work harder, increasing wear and tear on the system. That can lead to higher energy bills, more frequent repairs, and a shorter system lifespan.
Furnace Filter Replacement Made Easy
Want to make filter changes a habit? Here are a few tips:
- Write the date on the filter when you install it
- Set a calendar reminder every 1–3 months based on your usage
- Change it before peak heating or cooling seasons
- Include it in your regular HVAC maintenance plan
Contact Allied for More Information
Still asking yourself how often should you replace your furnace filter? That’s what we’re here for. At Allied Air Conditioning & Heating Corp., we’ve been helping homeowners in Palatine, Libertyville, and throughout Chicagoland since 1969. Call us today or reach out online to learn more or to schedule furnace maintenance.
