Maintaining proper airflow in a Coleman Evcon furnace hinges on knowing where the filter sits. The air filter protects the heat exchanger, blower, and coils from dust and debris while ensuring efficient operation. Locating the filter quickly saves time during routine maintenance and helps prevent higher energy use or furnace strain caused by a clogged filter. This guide explains common Coleman Evcon furnace filter locations, how to identify the correct size and type, and a straightforward replacement process. It also covers maintenance tips and troubleshooting for filter-related issues.

How To Locate The Filter On A Coleman Evcon Furnace

Every Coleman Evcon model can place the filter in a slightly different spot. In most units, the filter is in the return air path, either behind a front lower panel or inside a cabinet near the blower. The exact location can vary by model year and cabinet layout. Before you start, turn off power to the furnace at the switch or the circuit breaker to avoid accidental starts.

Typical Filter Locations

Return air plenum near the furnace, often behind a filter slot or grille
Front lower access panel on the furnace cabinet
Side access panel that exposes the blower compartment
Some older Evcon models place the filter in the return duct just ahead of the furnace

Steps To Confirm The Filter Location

Open the front panel or bottom door to access the blower compartment.
Look for a rectangular frame or slot labeled “Filter” or showing airflow arrows.
Note the filter type (air flow direction is toward the furnace). If no slot is visible, check the return ductwork or the owner’s manual.
Take a quick photo for reference if needed and record dimensions before purchasing a replacement.

How To Identify The Right Filter Size And Type

Knowing the correct filter size and type is essential for proper airflow and efficiency. The Coleman Evcon system typically uses 1-inch thick disposable filters, though some models use thicker 4-inch media filters. If the current filter is present, measure its dimensions from edge to edge and note the thickness. When in doubt, remove the filter, read the dimensions printed on the frame, and replace with the same size and MERV rating recommended by the furnace manual.

Filter Size And Type Considerations

Thickness: Most residential Evcon units use 1″ or 2″ thick filters; some premium units use 4″ filters.
Dimensions: Common residential sizes include 16×20 inches, 20×25 inches, and 14×20 inches; measure the opening precisely.
Filter type: Pleated paper or non-pleated electrostatic filters; avoid high-MERV filters that restrict airflow in older systems. A MERV rating between 8 and 11 is typically a good balance.
Brand compatibility: Use the filter type recommended in the owner’s manual or on the existing filter frame.

For homes with pets, high dust, or allergy concerns, a slightly higher MERV (within the system’s airflow tolerance) can help, but never exceed what the furnace is designed to handle.

Step-By-Step Guide To Replacing The Filter

Power down the furnace at the thermostat and switch off the circuit breaker to ensure safety.
Access the filter compartment by removing the front lower panel or blower access panel.
Remove the old filter and check its size; note the orientation arrows on the new filter.
Clean the slot area if there is dust buildup and confirm the airflow direction ensures air moves toward the blower.
Insert the new filter fully into the slot, with arrows pointing toward the furnace.
Reattach the access panel securely and restore power to the furnace.
Turn on the system and run a brief cycle to confirm proper airflow and no unusual noises.
Record the replacement date and set a reminder for the next change.

Maintenance Tips And Replacement Schedule

In most homes, replace the filter every 1 to 3 months. Factors that affect frequency include system usage, the presence of pets, dust levels, and whether someone in the home has allergies. Check filters monthly during peak heating season. If air feels stuffy or energy bills rise, inspect and replace sooner. A dirty filter can reduce airflow, cause the evaporator coil to ice up, and decrease heat output. Always keep spare filters on hand for quick changes.

Pets or high dust environments: change every 30 days
Moderate use: every 60–90 days
Low use or frequent cleaning: every 90–180 days
Inspect for bent edges and proper seating to ensure an airtight fit

Troubleshooting Common Filter-Related Issues

Poor airflow after replacement: Ensure the filter is not too thick for the slot and seated correctly with the arrow toward the blower.
Noisy operation: A mis-seated or warped filter can cause rattling; reseat or replace.
Short cycling: A clogged filter may trigger ongoing cycling; replace and inspect the blower or limit switch.
Energy inefficiency: A consistently dirty filter increases energy use; implement regular checks.
Damage or misfit: If the slot or frame is damaged, contact a professional; forcing a filter into a damaged slot can cause further issues.