Auto- or self-defrost is a common feature in almost all refrigerators. These appliances are referred to as frost-free and they regularly defrost the evaporator inside them. After every defrosting cycle, the excess liquid and dirt is discarded in the refrigerator's drain pan, through the drain tube. From a sanitary point of view, cleaning the drain pan is a good idea and a part of a regular maintenance. But the drain tube can also get clogged, which usually manifests as water build-up at the base of the fridge. Either way, the refrigerator drain needs to be thoroughly cleaned and maintained.
Unplug your refrigerator from a power source. This is always the first thing to do when engaging in refrigerator repair or maintenance.
Locate the drain hole inside the base of your refrigerator. If necessary, remove trays or plastic shelves to access it. If you can't find the drain hole right away, check the owner's manual.
Remove the plug from the drain tube simply by lifting it.
Inspect the inside of the drain tube to check if there's any ice build-up. If there is, use a blow dryer to melt the ice and make it flow to the drain pan.
Insert a thin wire brush inside the drain tube and move it around to remove the clog or any dirt build-up. Check the drain pan to see if anything was pushed out through the tube. Note that the drain pan is usually under the fridge.
Rinse the drain tube with hot water with an addition of a liquid detergent and a few teaspoons of bleach. Leave the drain tube to thoroughly dry before plugging the fridge back in.
Remove the drain pan, empty it and thoroughly clean it with the same cleaning solution. Use a wire sponge if the dirt inside the drain pan is encrusted.
Place the drain pan back into its position. Put back all the trays and shelves and the drain plug. Then close the refrigerator door and plug it back in.
The drain pan and the drain tube collect a lot of bacteria and dirt, so make sure to clean both of them with an antibacterial cleaning solution. You can also try cleaning your fridge drain with vinegar instead of bleach.
Always wear protective rubber gloves when cleaning your fridge's drain assembly.