Leaks in water lines may damage decay or mold growth between the floor and sub floor. Refrigerators without water lines can harbor mold growth in the drip tray beneath the unit and also inside the doors and seals. Drip pans should be emptied and cleaned every three months. The refrigerator coil accumulates dust and pet dander and can be a source of allergens. The coils and exterior of the appliance should be cleaned regularly.