Coleman air conditioner emits a musty or moldy odor when it starts.

Safety: Turn OFF power before accessing the coil. Wear gloves and a mask if sensitive to mold.

• Inspect coil and pan: Remove the access panel and examine the evaporator coil and drain pan for slime, mold, or debris.
• Clean coil: Use a no-rinse evaporator coil cleaner approved for HVAC use. Follow label directions.
• Disinfect pan: Clean the drain pan with a mild bleach solution (if compatible with materials) or an HVAC-approved pan treatment. Rinse thoroughly.
• Improve filtration: Install a higher-quality filter compatible with your Coleman air handler to reduce debris entering the coil.
• Run fan: After cleaning, run the fan-only mode for 30–60 minutes to help dry the coil and pan.

Note: Consider UV lights designed for HVAC coils if odors persist and local codes allow.