I have a Whirlpool refridgerator/freezer that is only 2 years old. I do not have the model number available at this time. I have had a problem with it not freezing ice and losing the cooling ability. I have unplugged the unit and took everything out of it. It had a good inch layer of ice/frost on the back bottom of the freezer section. I am not sure if this was the problem but would like to investigate what others might think.

Your problem is with the self defrost system.