Freezer ice build up

The freezer has ice build up on the bottom of freezer. I turned off ice maker and removed the ice build up. Let sit for 2 days and again ice has started to build up. I noticed the drain on the back of the freezer was plugged.
How or why does the drain get plugged with ice.

I have unplugged water line. Thought I would use some hot water to try and unplug drain.

Hi,

This problem has nothing to do with the water line. The cause of the problem is a clogged drain. Defrost it and run some hot water through the drain. A turkey baster may help. Make sure the other end of the drain is clean.

Gene.