Strong musty or moldy smell from indoor unit when starting

Safety first: Turn OFF and unplug the unit before cleaning. Wear gloves and a mask if sensitive to mold.

Steps:

• Clean filters: Wash filters thoroughly with mild detergent and dry completely.
• Clean coil: Use a foaming coil cleaner approved for AC units. Apply to the evaporator coil and allow it to drain into the pan.
• Clean drain pan: If accessible, wipe the pan with a cloth and mild disinfectant solution.
• Run fan‑only mode: After cleaning, run the unit in fan‑only mode for 30–60 minutes to dry the coil.

For persistent odor: Professional deep cleaning with specialized chemicals and tools may be required.