Goodman Furnace Filter Location: Find, Check, and Replace Your Filter

Trying to find the Goodman furnace filter location? This guide explains where the filter usually sits on Goodman gas furnaces, how to identify your setup, and the right way to replace the filter. Because Goodman does not always place a factory filter inside the furnace, the exact location often depends on installation. Use the steps and diagrams-in-words below to spot your filter fast and keep your system running efficiently.

Quick Answer: Most Common Goodman Furnace Filter Locations

The filter is almost always on the return-air side—where room air enters the system—never on the supply side. On Goodman furnaces, expect one of these locations:

• External filter rack on the side of the furnace cabinet, with a metal slot and a removable cover.
• Bottom return under an upflow furnace, with the filter sliding in at the base of the cabinet.
• Return-air grille in a hallway, ceiling, or wall, holding a 1-inch filter behind the grille.
• Media air cleaner cabinet mounted between the return duct and furnace, holding a 3–5 inch thick filter.
• Horizontal mount return-end slot where the duct meets the furnace, often with a sheet-metal pull tab or cap.

If none of these are present, the system may have multiple return grilles, or the installer may have omitted a filter—something to correct quickly to protect the blower and heat exchanger.

How To Locate The Filter On A Goodman Furnace (Step-By-Step)

Before You Start

Turn off the furnace at the switch or breaker for safety. Have a flashlight ready. Look for an equipment label inside the blower door for your model number, which can help identify cabinet width and typical filter options.

Identify Your Airflow Orientation

The filter sits on the return side of the system. Determine whether your Goodman furnace is upflow, downflow, or horizontal. The direction of airflow determines where the return air enters—and that is where the filter should be.

• Upflow: Air enters through the bottom or side; warm air leaves the top into the supply plenum.
• Downflow: Air enters from the top; warm air leaves the bottom into floor ducts.
• Horizontal: Air enters one end; warm air leaves the other end.

Upflow Installations: Most Common Filter Spots

On an upflow Goodman furnace, the return typically connects to the bottom or side of the cabinet. Check for:

• Side filter rack: A slot with a removable cover on one or both sides of the furnace near the base.
• Bottom filter slot: A filter slides into a track under the blower compartment; access may be from the front or side.
• Media cabinet: A thicker cabinet between return duct and furnace, usually 16–25 inches tall with an access door.
• Return grille: Large wall or ceiling grille with filter clips behind the grille face.

Downflow Installations: Look Above The Furnace

On downflow systems, the return duct enters from the top of the furnace. A filter is usually in:

• A filter rack or media cabinet placed above the furnace where the return duct connects.
• Return grilles that hold filters in the ceiling or wall, especially in homes with multiple returns.

Because supply air exits the bottom on a downflow, never place a filter on the bottom discharge—only on the return side on top or at return grilles.

Horizontal Installations: Check The Return End

In horizontal configurations, the filter is commonly at the return end of the furnace. Look for a metal slot, screw-on panel, or media cabinet on the end where the return duct attaches. Some installations use a return grille filter instead.

Where Is The Filter On Specific Goodman Models?

Goodman furnaces share similar cabinets across model families. The filter location depends on the return configuration rather than the specific model number. Use this table as a quick reference.

Tip: Goodman furnaces are often shipped without an internal filter. If no slot or cabinet is attached to the furnace, check the return duct or return grilles for the filter.

External Filter Racks And Return Grilles

How To Spot An External Filter Rack

A furnace-mounted filter rack is a rectangular metal housing attached to the cabinet side or base. It usually has a removable cover plate or a spring clip. The filter slides in flat, with the airflow arrow pointing toward the furnace.

Return Grille Filters

Large wall or ceiling returns often include a filter frame behind the grille. The grille swings down after releasing latches or screws. Homes may have multiple returns, each with its own filter—replace all at the same time.

Media Air Cleaners And Cassettes

Many Goodman systems use a media air cleaner between the return duct and furnace. These cabinets hold 3–5 inch thick filters with a long service life. Common brands include Clean Comfort/Goodman AM11 or AM14, Aprilaire, Honeywell, and Air Bear.

• Identify by a side access door labeled with the brand and filter size.
• Filters slide into tracks; arrows should point toward the furnace.
• Typical sizes: 16x25x4, 20x25x4, 20x20x4, 24x25x4, and 16x25x5.

When a media cabinet is present, the furnace usually does not have a 1-inch rack in use. Avoid double-filtering; too many filters add restriction.

Filter Sizes, Thickness, And MERV Ratings

Common Sizes On Goodman Furnaces

Goodman furnace filter sizes vary by cabinet width and return opening. Common 1-inch sizes include 14x25x1, 16x25x1, 20x25x1, and 24x25x1. Bottom returns on wider cabinets may take 20x25x1 or 24x25x1. Always measure before purchasing.

Cabinet Width And Typical Filter Pairings

For media air cleaners, 4–5 inch filters like 16x25x4 or 20x25x4 are typical. Match the cabinet label exactly for best performance and fit.

MERV Ratings For Goodman Systems

• MERV 8–11 is a safe range for most residential Goodman furnaces, balancing filtration and airflow.
• MERV 13 offers better capture of fine particles but can raise static pressure. Use only if the system and ductwork can handle it, ideally with a 4–5 inch media filter.
• Avoid cheap fiberglass filters that pass too much dust. Pleated filters are generally better.

Too-restrictive filters can trip high-limit safeties, reduce comfort, and stress the blower. When in doubt, choose a larger surface area filter (bigger size or thicker media) over a higher MERV in a thin filter.

Replacement Interval And Signs The Filter Needs Attention

Check 1-inch pleated filters every 30 days and replace every 60–90 days under normal conditions. Large 4–5 inch media filters often last 6–12 months. Frequency depends on pets, dust levels, smoking, renovations, and fan runtime.

• Visible dust mat or gray layer on the filter surface.
• Rooms feeling stuffy, or rising energy bills.
• Longer heat cycles or short-cycling.
• Reduced airflow at supply registers.

Set a calendar reminder or label the filter frame with the installation date. Consistent replacement protects the heat exchanger, blower wheel, and indoor coil.

How To Replace A Goodman Furnace Filter Safely

Tools And Safety

Turn off power at the disconnect or breaker. Wear gloves and a dust mask if sensitive to dust. Keep a trash bag nearby for the old filter.

Step-By-Step Replacement

1. Locate the filter. Identify the rack, media cabinet, or return grille holding the filter.
2. Note airflow direction. The arrow on the filter frame should point toward the furnace or blower.
3. Remove the cover. Release the latch or unscrew the panel on the rack or cabinet. For grilles, open the latches gently.
4. Slide out the filter. Pull straight to avoid bending. Take note of size and brand.
5. Vacuum the slot. Lightly clean the rack area to reduce debris and ensure a good seal.
6. Insert the new filter. Match the size and orientation. Push until fully seated with no gaps.
7. Seal and close. Replace the cover or grille. If a rack uses a cover plate, ensure it’s tight to prevent bypass air.
8. Restore power and test. Run the blower and check for rattles or whistles indicating an air leak.

Important: If the new filter collapses or whistles, it may be too restrictive or the rack may be undersized. Consider a larger media cabinet to lower resistance.

If You Can’t Find The Filter

Some installations omit a filter or hide it at a distant return grille. Use this checklist:

• Scan all large return grilles; check behind the grille face for clips.
• Inspect the return plenum for a factory or field-built rack near the furnace.
• Look for a media cabinet between the return duct and furnace.
• Trace the return duct from the furnace back to the nearest grille.

If no filter exists, install one immediately. A simple sheet-metal filter rack on the return duct or a media cabinet are effective solutions. For multiple returns, either put filters at each grille or centralize filtration in a media cabinet sized for total airflow.

Common Mistakes And How To Avoid Them

• Wrong airflow direction. Arrows must point toward the furnace; reversed filters reduce airflow and filtration.
• Double filtering. Stacking a 1-inch filter with a 4–5 inch media filter increases static pressure. Use only one designed approach.
• Undersized filters. A small filter in a high-capacity system can cause noise and heat-limit trips. Upsize the filter area when possible.
• Gaps and bypass. Missing rack covers or loose grilles allow unfiltered air to bypass the filter, dirtying the blower and coil.
• Overly high MERV in 1-inch filters. MERV 13 in a thin filter can be too restrictive for some duct systems.
• Skipping replacement. A clogged filter overheats the furnace and shortens component life.

“Diagrams In Words” For Rapid Identification

Upflow With Side Return

Return duct attaches to the side of the furnace near the blower section. Look for a horizontal slot with a small cover plate and a hand grip. Remove the plate; the 1-inch filter slides in and out.

Upflow With Bottom Return

Furnace sits on a return box or platform. The filter slides into a tray at the bottom front or side. Sometimes a small access panel on the front base releases with quarter-turn fasteners.

Downflow Furnace

Return duct connects at the top of the furnace. A media cabinet or rack is installed between the top duct and furnace top panel. No filter is placed on the bottom supply outlet.

Horizontal Furnace

Furnace lies on its side. The return duct connects to one end; the filter rack or cabinet is at that end. A narrow access plate or door reveals the filter tracks.

Return Grille System

Large ceiling or wall grilles have hinges and latches. Open the grille to reveal a 1-inch filter in a spring-loaded frame. Some homes have several returns—check and replace all.

Airflow, Static Pressure, And Efficiency: Why Location Matters

The correct Goodman furnace filter location ensures the blower receives adequate air with minimal restriction. Poorly placed or undersized filters raise static pressure, which reduces airflow, increases noise, and can trigger high-limit shutdowns during heating.

Locating the filter at the furnace inlet or in a properly sized media cabinet helps keep dust off the blower wheel and secondary heat exchanger, preserving efficiency and reliability.

How To Measure For The Right Filter

• Measure the rack opening. Check width and height of the slot the filter slides into. Use the nearest standard size (e.g., 16×25).
• Confirm thickness. 1-inch for standard racks; 3–5 inches for media cabinets. Do not force a thicker filter into a 1-inch rack.
• Check cabinet width. Narrow cabinets tend to use 14–16 inch wide filters; wider cabinets may use 20–24 inch widths.
• Match the cabinet label. Media cabinets list the exact replacement size and model.

Write the size on the furnace with a marker for quick reference. Consistency helps avoid guesswork during the next changeout.

Troubleshooting: Symptoms Of A Filter Problem

• Hot furnace cabinet or frequent limit trips: Filter may be clogged or too restrictive.
• Whistling at the filter rack: Gaps or an undersized filter. Add a proper cover or upsize the rack.
• Excess dust in the home: Filter bypass, wrong MERV, or missing filter at a secondary return grille.
• Uneven room temperatures: Low airflow from a dirty filter; replace and recheck.

Persistent issues may indicate duct restrictions or an improperly sized return. An HVAC technician can measure static pressure and advise on upgrades, such as a larger media cabinet.

Seasonal Tips For American Homes

• Heating season: Inspect filters at the start of fall. Cold snaps increase runtime; check more often during extreme weather.
• Cooling season: If the furnace shares a blower with central AC, keep filters clean to protect the evaporator coil from clogging.
• Allergy season: Consider MERV 11 or a 4–5 inch media filter for better pollen capture, ensuring airflow remains adequate.
• Home projects: During sanding or painting, use a lower-cost filter and replace it immediately afterward.

Energy And Cost Considerations

Clean filters lower energy use by reducing blower workload and improving heat transfer. A well-sized 4–5 inch media filter can offer lower pressure drop than a 1-inch high-MERV filter, extending filter life and lowering total cost of ownership.

Buying filters in multi-packs and replacing on schedule is often less expensive than running the system with a partially clogged filter that can lead to repairs.

FAQs: Goodman Furnace Filter Location And Replacement

Where Is The Filter On A Goodman Furnace?

On the return-air side. Common spots include a side or bottom rack on the furnace, a media cabinet between the return duct and furnace, or inside return grilles. Downflow units typically have the filter above the furnace.

What Size Filter Does A Goodman Furnace Use?

Sizes vary by cabinet width and install. Common 1-inch sizes are 14x25x1, 16x25x1, 20x25x1, and 24x25x1. Media sizes include 16x25x4 and 20x25x4. Measure your rack or check the media cabinet label.

Which Way Does The Filter Face?

Arrows point toward the furnace (toward the blower). At a return grille, arrows point into the duct toward the furnace.

How Often Should The Filter Be Replaced?

Check monthly. Replace 1-inch pleated filters every 60–90 days. Replace 4–5 inch media filters every 6–12 months, or sooner in dusty conditions or homes with pets.

Can I Use MERV 13 In A Goodman Furnace?

Yes, if the system is designed for the added resistance, preferably with a 4–5 inch media filter. For 1-inch filters, MERV 8–11 is safer for most duct systems.

What If My System Has Multiple Return Grilles?

Replace all return grille filters on the same schedule, or convert to a central media cabinet and remove the grille filters to avoid double-filtering.

Why Does My Furnace Not Have A Filter Slot?

Many Goodmans are installed with filters at return grilles or in media cabinets. If neither exists, a filter rack may be missing and should be added to protect the equipment.

Are There Model-Specific Filter Locations?

Goodman model families share similar cabinet designs. Filter location depends more on whether the system is upflow, downflow, or horizontal, and how the installer connected the return duct.

When To Call A Professional

Contact a licensed HVAC technician if the filter is not accessible, the rack is damaged, the system trips limits after a filter change, or static pressure is high. A pro can measure airflow, seal bypass paths, and recommend a right-sized media cabinet for your Goodman furnace.

Key Takeaways For Finding A Goodman Furnace Filter

• Return side only: The filter protects the furnace blower; it is never on the supply side.
• Location depends on installation: Check side or bottom racks, media cabinets, and return grilles.
• Orientation matters: Airflow arrows must point toward the furnace or blower.
• Size and MERV must match the system: Use MERV 8–11 in 1-inch filters or a 4–5 inch media filter for higher MERV.
• Maintenance saves money: Routine replacement improves comfort, efficiency, and equipment life.

With the right filter in the right place, a Goodman furnace can deliver consistent comfort, cleaner indoor air, and longer service life. Use this guide to pinpoint your Goodman furnace filter location, select the correct size and rating, and replace it safely and on schedule.