Strong musty or moldy smell when the air conditioner starts.

Safety first: Turn off power before deep cleaning.

Steps:

• Clean filters: Wash Bosch filters thoroughly and dry.
• Use coil cleaner: Apply a non-rinse foaming evaporator coil cleaner suitable for AC units to the indoor coil following product instructions.
• Clean drain pan: Wipe the pan with a cloth and a mild disinfectant solution, avoiding electrical components.
• Run in Fan mode: After cleaning, run the unit in Fan-only mode for 30–60 minutes to dry the coil and reduce future mold growth.

Persistent odor: Consider professional chemical cleaning of the Bosch indoor unit.