Goodman air conditioner emits a musty or moldy smell when running

Safety first: Turn off power to the indoor unit before opening panels. Wear gloves and a mask if you are sensitive to mold.

Steps to reduce odor:

• 1. Replace filters: Install new, properly sized filters in the Goodman air handler or furnace.
• 2. Inspect coil and pan: Remove the coil access panel and visually inspect the evaporator coil and drain pan for slime or mold.
• 3. Clean drain pan: Use a mild detergent solution or coil cleaner approved for indoor use to clean the pan. Rinse carefully without spilling water into the furnace or electrical components.
• 4. Treat drain line: Pour a cup of white vinegar into the condensate drain to inhibit algae growth.
• 5. Adjust fan mode: Set the thermostat fan to AUTO instead of ON to allow the coil to dry between cycles, reducing mold growth.

When to call a professional: For heavy biological growth, have a technician perform a thorough coil cleaning and evaluate for UV lights or improved filtration.