My Maytag top mount fridge (MTB1954DRW) is 14 years old. I started noticing ice forming on the inside of the freezer door. I thought I simply needed to change the freezer door seal. When I removed the old seal and the freezer door liner, I found that behind the liner it was literally filled with ice. Frozen in the ice was a ring of foam insulation. It took me an hour with a blow dryer to remove the ice! My questions are this:

1) The piece of foam insulation appeared to be attached to nothing. I do not see the piece of foam insulation in any parts diagrams for my fridge online. What is its function if it just lies in there? Do I need to dry it out and put it back in place when I reassemble? Do I need to replace it?

2) What is the likely cause of this huge ice build-up? Is it possible that a new seal will fix this, or is there likely to be a bigger problem?

Thanks for your help, Dmitri