Freezing water line

Question

Whirlpool upright Freezer Mod#EV150NXGW00Ser# EWJ1668330 It has a door lock.line leading to the pan below freezes up.The door also freezes and lets the water out whenI remove all items and thaw completely. I have cheked to make sure the line is open each time I have thawed it.Thanks for any help you can give me.d**k potosh