My fridge/freezer drain hole is blocked. How can I clear it?

Clearing a blocked defrost drain hole inside a residential refrigerator or freezer compartment requires a careful manual cleaning process to restore proper water drainage. First, unplug the refrigerator and remove food items, shelves, and the back freezer panel to expose the frozen drain trough beneath the evaporator coils. Second, use a hair dryer on a warm setting or pour warm water mixed with a little baking soda down the drain hole to melt any solid ice plug. Third, insert a flexible pipe cleaner, a small bottle brush, or a piece of flexible wire gently down the drain tube to push out trapped food debris or slime. You can troubleshoot drainage flow easily. You can verify that your clearing procedure was successful when pouring a small cup of water into the internal drain trough results in water flowing unimpeded into the evaporation pan beneath the fridge without pooling.