Strong musty or moldy smell when the unit starts

Safety: Turn off power. Wear gloves and a mask if you are sensitive to mold.

Steps:

• Clean filters: Wash thoroughly with soap and water and dry in the sun if possible.
• Clean evaporator: Use an AC-safe foaming coil cleaner sprayed onto the evaporator fins. Allow it to work and drain away.
• Disinfect drain pan: Wipe the drain pan with a mild bleach solution (if compatible with materials) or a commercial coil disinfectant.
• Run fan mode: After cleaning, run the unit in Fan Only mode for 30–60 minutes to dry the coil.

Severe contamination may require professional deep cleaning.