I've defrosted the freezer once already due to water leaking out the front bottom. Ice buildup was all over the fins and not allowing cold air to circulate to the upper fridge. I cleared in all out and made sure it was working. Put a new gasket on the freezer door. Now I'm back to the bad ice buildup again. Water isn't leaking yet but the fridge is warm and no air is getting up there. What do I need to do to make sure it doesn't happen every three months??