When using the Rheem split system furnace, you have still run your system continually and yet you still find your home stuffy or even dusty, your air filter may be the cause of your problem. Through time, dust, pets, and other particles accumulate in your filter, thus stimulating your furnace to work harder than necessary. The result? Increased energy costs, stuffy air, and air that does not feel as cool as it’s supposed to.
The best part? The Rheem air filter replacement is easy, cheap, and highly efficient. Learning how to change a Rheem air filter in a split system furnace involves only a few simple steps that will help you restore proper airflow, make your home more efficient, and breathe appreciably cleaner air every day.
Top Takeaways
Changing your Rheem air filter regularly keeps your air clean and system efficient.
Replace filters every 45–90 days depending on pets, allergies, and air quality.
MERV 11–13 filters offer the best balance for most homes.
Better airflow means lower energy costs and a longer furnace life.
A simple habit like filter replacement makes a noticeable difference in comfort and health.
Why Changing Your Rheem Air Filter Matters
Think of your air filter as your furnace’s lungs — it needs clean air to function properly. When that filter gets clogged, airflow slows down, dust spreads more easily, and your furnace must push harder to do its job.
Here’s what a dirty filter can cause:
Dust buildup around vents and furniture
Higher utility bills and more frequent breakdowns
Reduced heating and cooling performance
Poor indoor air quality and allergy flare-ups
Changing your Rheem air filter regularly is one of the easiest ways to protect your system and your health — no tools, no stress, just a cleaner, healthier home.
How to Change a Rheem Air Filter in a Split System Furnace
You don’t need to be an HVAC expert to replace your Rheem air filter. Just follow these simple steps — it takes less than 10 minutes.
Turn Off the System
Always start by switching off your HVAC system at the thermostat. This keeps dust from circulating and protects your unit while you work.
Find the Filter Compartment
For most Rheem split system furnaces, the filter is located:
Behind the return air vent
Inside the return duct near the air handler
In a slot between the furnace and air plenum
Remove the Old Filter
Slide out the old filter carefully. Look for an airflow direction arrow printed on its side — you’ll need to match that when installing the new one.
Check the Size and Type
You’ll see the size printed on the frame (for example, 20x25x1). Rheem filters also show a MERV rating — MERV 8 for basic filtration, MERV 11 for pet dander and pollen, or MERV 13 for advanced allergen protection.
Insert the New Filter
Slide the new filter in with the airflow arrow pointing toward the furnace. It should fit snugly without bending or forcing it.
Turn Your System Back On
Once the new filter is in, turn your system back on. You’ll likely notice smoother airflow and fresher air almost immediately.
“Homeowners often underestimate how much impact a clean filter has. Even one missed replacement can make your Rheem furnace work 20% harder than it needs to.”
Case Study: Cleaner Air, Lower Bills, Happier Home
A homeowner in Atlanta noticed that their home wasn’t heating evenly and the air felt heavier than usual. They hadn’t changed their air filter in over six months — something many homeowners forget.
After installing a new Rheem MERV 11 filter, the results were immediate:
Airflow improved noticeably
Dust accumulation dropped within a week
The system ran quieter
Energy use dropped by nearly 12% the next month
A simple filter change turned into better air, lower bills, and a more comfortable home.
Supporting Statistics & Insights
Indoor air can be 2–5 times dirtier than outdoor air.
According to the EPA, replacing filters regularly is one of the most effective ways to reduce indoor pollutants like dust, pollen, and smoke.
Source: EPA – Indoor Air QualityDirty filters cost you money.
The U.S. Department of Energy found that clean filters can reduce HVAC energy use by 5–15% — a small change that adds up over time.
Source: Energy.gov – HVAC MaintenanceClean air = healthier living.
The American Lung Association emphasizes that proper air filtration reduces asthma and allergy triggers, especially in homes with children and pets.
Source: ALA – Indoor Air Pollutants
Final Thoughts & Recommendations
Replacing Filters of your Rheem air is a little job with a huge reward. It not only makes your air cleaner but it also wears your furnace less, instead, it makes your system more efficient and saves you money and brings your comfort all year round.
Quick Recommendations:
Change filters after 60 90 days, after 45 days in case of pets or allergies.
Check direction of airflow always prior to installation.
Install MERV 11 or 13 to do a superior filtration.
Always have some spare filters just in case you do not catch one.
Your HVAC system — and your lungs — will thank you.
Next Steps: Simple Maintenance Checklist
Check your current filter’s size and MERV rating.
Buy the correct Rheem replacement filter.
Replace your filter every 2–3 months (more often in allergy season).
Vacuum vents and grilles monthly.
Schedule a yearly HVAC tune-up for long-term efficiency.
Frequently Asked Questions
What then is the maximum replacement of my Rheem split system furnace filter?
It should be done every 60-90 days or every 45 days in case of pets or in a dusty place. Frequent change can be used to keep the air flowing and cost-effective.
But then how do I get the correct size filter?
Inspect the frame of the old filter or the frame of the old filter or your Rheem manual. It is also printed on the edge in large size and one should compare the nominal and actual measurements.
Can I change my Rheem system to have a greater MERV rating filter?
Indeed, Rheem systems can go to MERV 13. The greater the rating, the smaller the size of the particles such as pollen, smoke as well as fine dust.
What will happen in the event that I forget to change the air filter?
It will make your furnace labor more, the air will be less, and dust will run in your home. It may lead to overheating or damage of the blowers in the long run.
Will it require a technician to change the filter?
Nof course, the majority of homeowners can accomplish it within minutes. However, it is always a good idea to plan HVAC maintenance with a professional on an annual basis.
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