Understanding where the filter sits on a Concord furnace helps homeowners improve efficiency and indoor air quality. The exact location can vary by model and installation, but several common setups recur across Concord units. This guide explains where to look, how to confirm the slot, and how to replace filters correctly. It covers typical sizes, orientation, and practical maintenance steps to simplify routine upkeep. Whether the furnace is in a utility closet, basement, or garage, knowing the Concord furnace filter location saves time and reduces the risk of running with a dirty filter.
Where To Look For The Filter On A Concord Furnace
The filter on a Concord furnace is usually placed in one of two main locations: in the return air path just before the blower, or inside the furnace cabinet behind an access panel. The exact model and installation determine which location is used. In many homes, the return air plenum or filter slot sits behind a removable grille or shield in the furnace closet. Some units instead have a filter slot on the inside of the cabinet, accessible after removing a service door.
Typical Locations
- Return air plenum: A filter slot or tray is often located where the return duct meets the furnace, pulling air from the house into the system.
- Front or access panel: A door on the front of the furnace may conceal a filter slot behind it.
- Bottom or side access: Some Concord models place the filter in a slot at the bottom or side of the cabinet, requiring removal of a panel.
- Inside the blower cabinet: In several configurations, the filter sits just ahead of the blower, inside the housing.
- Labelled indicators: Look for arrows on the filter or frame showing airflow direction toward the furnace.
To confirm the exact location, consult the unit’s manual or model number online. If the model is older or has an aftermarket installation, the slot may differ from typical layouts.
Steps To Identify The Filter Slot On Your Concord Furnace
- Power off: Switch off the furnace at the thermostat and circuit breaker to ensure safety during inspection.
- Open the access: Remove the service panel or front door as required by the model. Use a flashlight to illuminate the interior.
- Look for a rectangular slot: Identify a clean, removable filter frame or a slot with a filter already installed.
- Check orientation: Note the arrow on the filter frame indicating airflow direction—arrows should point toward the furnace.
- Examine the slot label: Some units have a small label inside the cabinet with filter size and type information.
- If not found: If no obvious slot is visible, consult the owner’s manual or search by the Concord model number; consider calling a technician if needed.
Common Filter Sizes And Types For Concord Furnaces
Residential Concord furnaces typically use standard 1-inch-thick filters, though higher‑efficiency setups may employ 2–4 inch thick options. Knowing the common sizes helps you stock replacements and avoid forcing a filter into an incompatible slot.
| Filter Size (inches) | Common Use | Typical Location |
|---|---|---|
| 16 x 20 x 1 | Standard residential filter | Return plenum or cabinet front |
| 20 x 25 x 1 | Another common 1-inch size | Return path or blower housing |
| 16 x 25 x 1 | Compact installations | Return or cabinet side |
| 14 x 20 x 4 | Higher efficiency, deeper filter | Balancing unit or larger return plenum |
| 16 x 25 x 4 | Extended airflow and filtration | Blower cabinet or dedicated slot |
When selecting a filter, match the size to the slot exactly and ensure the frame fits without bending. For efficiency debates, a MERV rating between 8 and 13 provides better filtration for homes with pets or allergies, while keeping airflow adequate for most Concord systems. Always avoid overly thick filters in slots not designed for them, as restricted airflow can strain the furnace.
Maintenance Tips And Replacement Best Practices
- Replace on a schedule: Most households replace every 1–3 months, depending on usage, pets, and allergies. In high-demand periods, check monthly.
- Keep the slot clean: Wipe the frame and housing when replacing to prevent dust buildup that can affect airflow.
- Check the orientation: Ensure the filter arrows point toward the furnace so air flows correctly through the filter.
- Use matching sizes: Always use the exact size specified for the slot to avoid gaps or improper seating.
- Inspect for wear: Look for bent frames, torn filter media, or signs of moisture; replace if damaged.
- Store spares nearby: Have a small stock of common sizes for quick changes to minimize system downtime.
Troubleshooting If You Can’t Find The Filter
If the Concord furnace filter location is elusive, verify each potential area: return plenum, front access, bottom or side panels, and inside the blower housing. Use the model number from the rating plate to pull the official installation guide online. If the system is older or modified, a professional HVAC technician can identify the correct slot and verify that the airflow pathway is not blocked or misdirected. Regular filter maintenance remains a key factor in furnace efficiency and indoor air quality.