Remove the shelf’s and food from the freezer then take out the panel at the back of freezer. You will see ice build up in the drain pan below the evaporator. Melt ice with hairdryer/heat gun then once the ice is clear you will see a hole in pan that leads to drain tube. Pour some hot water in pan, wait a couple minutes. Mop up water and repeat this step 2-3 times....once you have done this find some flexible curtain wire or electrical wire and poke it down the hole until you see the water drain. Now it is clear.