OEM replacement air filter for Coleman Mach 6798-309 Series ducted ceiling assemblies used on most Fleetwood RV units. Non-allergenic fabric, hand washable and reusable. Single filter.
The Coleman Mach 6798-3751 is the OEM replacement air filter for the 6798-309 Series ducted ceiling assembly — a configuration used on most Fleetwood RV units equipped with Coleman Mach ducted air conditioning. The filter sits in the return air path of the ceiling assembly and captures dust, debris, and airborne particles before they reach the evaporator coil.
Keeping the filter clean is the single most important maintenance task for RV AC performance. A clogged or missing filter restricts return airflow across the evaporator coil. Restricted airflow reduces cooling output and can cause the coil to drop below freezing, leading to ice buildup, compressor cycling, and potential system damage. Regular filter cleaning maintains proper airflow, protects the coil, and keeps the system running efficiently.
The 6798-3751 is constructed from non-allergenic fabric and is designed to be hand washed and reused rather than discarded. Wash with warm water and mild dish detergent, rinse thoroughly, and allow the filter to dry completely before reinstalling. Never reinstall a wet filter, as moisture in the return air path can promote mold growth and damage components.
OEM filter for Coleman Mach 6798-309 Series ducted ceiling assemblies — the configuration used on most Fleetwood RV units
Non-allergenic fabric construction — hand wash with warm water and mild dish detergent; air dry fully before reinstalling
Nominal 16" × 16" filter sized specifically for the 6798-309 Series ducted ceiling assembly return air opening
Backed by a 2-year limited manufacturer's warranty
To clean: Remove the filter from the ceiling assembly. Hand wash with warm water and mild dish detergent. Rinse thoroughly until water runs clear. Drying: Allow the filter to air dry completely before reinstalling. Do not reinstall a damp or wet filter. Frequency: Inspect and clean the filter regularly, particularly during heavy AC use seasons. A clogged filter restricts airflow and can lead to evaporator coil icing and reduced cooling performance.
Operating the AC without a filter allows dust and debris to collect directly on the evaporator coil. Coil contamination restricts airflow, reduces heat transfer efficiency, and can cause coil icing. Always ensure the filter is installed before running the system — including after cleaning while waiting for the filter to dry.
The 6798-3751 (16" × 16") is specifically for the 6798-309 Series ducted ceiling assembly used on most Fleetwood units. The visually similar 6798A3761 (15" × 15") fits the 8330, 8530, 9430, and 9630 Series ducted ceiling assemblies — a different group of Coleman Mach ACs. These filters are not interchangeable. Verify your ceiling assembly series before ordering.
Coleman Mach ducted ceiling assemblies use different filters depending on the model series. This table summarizes the available ducted filter options to help identify the correct replacement for your unit.