Finding the furnace filter location for a Concord HVAC unit is a common maintenance task that improves indoor air quality and system efficiency. This guide explains typical Concord filter locations, how to access and replace filters, recommended filter types, troubleshooting tips, and when to call a professional.
| Concord Furnace Model Type | Typical Filter Location | Common Filter Sizes |
|---|---|---|
| Upflow/Upblast Cabinet | Return Plenum / Blower Compartment | 16x20x1, 20x20x1, 16x25x1 |
| Downflow/Horizontal Cabinet | Lower Access Panel / Filter Rack | 20x25x1, 14x20x1, Custom |
| Air Handler / Packaged Unit | Return Air Grille / Filter Drawer | 16x25x1, 20x24x1, Media |
How Concord Furnace Filter Locations Vary
Concord furnaces are installed in different orientations: upflow (basement), downflow (closet or attic), and horizontal (crawlspace or attic). Filter location depends primarily on unit orientation and whether the air handler is an indoor cabinet or part of a packaged rooftop unit. Recognizing the orientation helps narrow the search for the filter quickly.
Common Concord Filter Locations
Return Air Grille (Wall, Ceiling, Or Floor)
Many installations put the filter at the return grille inside the living space. The grille frame may hold a disposable 1″ filter or a reusable electrostatic filter. Removing the grille or opening a slot reveals the filter. This is the easiest location for routine homeowner replacement.
Return Plenum Directly At The Furnace
Some Concord furnaces have the filter inside the return plenum where the return duct meets the furnace cabinet. A filter door or slide-out rack on the cabinet provides access. The filter may be 1″ thick or a larger media style. Check along the front or side of the unit for a removable access panel.
Blower Compartment Or Filter Drawer
On upflow or downflow units, the filter can sit in the blower compartment behind an access panel. The drawer or track system allows the filter to slide out for replacement. Always shut power off before opening the blower compartment.
Filter Rack In The Air Handler Or Horizontal Unit
Horizontal and some air handler installations include a dedicated filter rack accessible via a small door on the side of the cabinet. Filters in these racks are often larger or thicker than standard 1″ filters. Measure filter depth and face size before buying replacements.
Step-By-Step: How To Locate The Filter On A Concord Furnace
- Turn Off Power: For safety, switch the furnace power to OFF at the service switch or breaker.
- Identify Unit Orientation: Look at airflow direction: return air duct enters the furnace cabinet on one side—this is where the filter commonly sits.
- Inspect Return Grilles: Check wall, ceiling, and floor return grilles for a visible filter frame or slot.
- Examine Furnace Panels: Look for a small removable panel, sliding slot, or latch on the return side of the furnace cabinet.
- Check Blower Compartment: Open the blower access (after power off) and look for a filter beneath or beside the blower assembly.
- Measure Existing Filter: Note the length, width, and depth printed on the filter frame or measure directly to match replacements.
Tools And Safety Precautions
Minimal tools are required for filter replacement: a screwdriver for access panels, a flashlight to inspect tight spaces, and work gloves to protect hands. Always cut power to the furnace before accessing interior components. Avoid touching electrical parts and rotating components such as the blower wheel.
Recommended Filter Types For Concord Furnaces
Concord furnaces accept a range of filter media depending on the filter slot depth and furnace design. The most common options are disposable 1″ fiberglass or pleated filters, 4–5″ media filters, and washable electrostatic filters. Choose a filter that balances indoor air quality and airflow resistance for reliable operation.
MERV Rating Guidance
MERV (Minimum Efficiency Reporting Value) indicates particle capture efficiency. For most homes, a MERV 6–8 disposable pleated filter offers basic filtration without overloading the furnace. For improved air quality, MERV 8–11 is appropriate for homes without restrictive furnace designs. Avoid using filters above MERV 13 unless the furnace blower and duct system are rated for higher static pressure.
How To Read Filter Size And Replacement Intervals
Filter sizes are expressed as nominal dimensions (e.g., 16x20x1), which correspond to the filter face width and depth. Measure the actual filter or slot if unsure. Standard replacement intervals: 1″ filters: every 1–3 months; 4–5″ media filters: every 6–12 months; high-efficiency filters may require tailored schedules based on household conditions.
Troubleshooting Common Filter Location Questions
No Visible Filter In Return Grille
Some installations place the filter inside the furnace rather than at the grille. If no filter is visible at the grille, inspect the furnace return side or inside the cabinet. Another possibility is a remote filter box located in the return duct near the furnace.
Filter Slot Too Small For Standard Filters
Older or compact Concord units may use custom-sized or reusable electrostatic filters. Measure the slot dimensions and consider ordering a custom filter or compatible washable option instead of forcing a standard size.
Airflow Drops After Replacing With A High-MERV Filter
If the system struggles after installing a high-efficiency filter, the furnace blower may be unable to overcome added resistance. Revert to a lower-MERV filter or consult a technician to assess blower capacity and duct static pressure.
When To Call A Professional
Contact a licensed HVAC technician if any of the following occur: the filter location cannot be found after inspection; the furnace has unusual noises or performance issues after filter replacement; the system repeatedly trips the blower compartment door switch; or there is uncertainty about filter compatibility with the unit. Professionals can also install permanent filter racks or recommend filtration upgrades tailored to the HVAC system.
Best Practices For Filter Maintenance
- Keep A Replacement Schedule: Mark calendar reminders for filter changes based on filter type and household factors.
- Keep Extra Filters On Hand: Store common sizes at home to avoid running with dirty filters.
- Inspect Filters Monthly: Check for visible dust loading, pet hair, or discolored media and replace early if necessary.
- Seal Return Ducts And Grilles: Ensure return grilles and ducts have proper seals to prevent unfiltered air bypassing the filter.
Filter Sizing Tips And Measurement Guide
Measure the filter face across the front and side, then measure depth. If the filter is in a slot, measure slot interior dimensions. For boxed or media filters, measure both the filter face and the frame thickness. Buy filters that match the measured dimensions closely; a snug fit prevents air bypass around the filter.
Upgrades And Alternatives
For better air quality, consider upgrading to a 4″ or 5″ media filter, which provides higher dust holding capacity with modest airflow restriction. Whole-house electronic air cleaners or HEPA systems can further improve filtration but may need dedicated fan assistance or duct modifications. A professional assessment ensures compatibility and avoids undue strain on the Concord furnace.
Cost Considerations
Disposable pleated 1″ filters cost between a few dollars to $15 each depending on brand and MERV rating. Media filters range $30–$100. Professional inspections or upgrades vary by region but typically range from $100–$400 depending on work scope. Budgeting for routine filter replacements preserves system efficiency and reduces long-term repair costs.
Frequently Asked Questions
How Often Should A Concord Furnace Filter Be Replaced?
Replacement depends on filter type and home conditions: standard 1″ filters every 1–3 months, pleated filters every 3 months, and media filters every 6–12 months. Homes with pets or allergies may need more frequent changes.
What If The Filter Size Is Not Standard?
Measure the slot or frame and order a custom-sized filter or a washable electrostatic model. Some HVAC supply stores can cut media filters to fit specific dimensions.
Can The Furnace Operate Without A Filter?
Operating without a filter allows dust and debris into the blower and heat exchanger, causing efficiency loss and potential damage. Always use a correctly sized filter to protect the system.
Quick Checklist For Locating And Replacing A Concord Furnace Filter
- Turn off power to the furnace.
- Check return grilles in the living space.
- Inspect the return plenum and furnace cabinet for a filter door or slot.
- Open the blower compartment if no external slot is found.
- Measure current filter or slot dimensions before buying a replacement.
- Install the new filter with the airflow arrow pointing toward the furnace.
- Restore power and confirm normal operation.
Additional Resources
Manufacturer manuals for Concord furnaces, HVAC supply centers, and local licensed contractors are reliable resources for model-specific guidance. Gathering the furnace model number and serial number from the data plate helps technicians provide precise recommendations.
Key Takeaway: Locating the Concord furnace filter depends on unit orientation and installation; common locations include the return grille, return plenum, blower compartment, or filter rack. Proper identification, correct filter sizing, and routine replacement maintain system performance and indoor air quality.