Freezer frost. I have a 5 year old freezer that I do not believe is a frost free model. It

Question

I have a 5 year old freezer that I do not believe is a frost free model.  It is frosting up pretty good inside, we ar having to manually defrost is twice a year? the door seal does not look bad or have any cracks that I can find.  Any suggestions?

model# UL2494ECW8 / serial # WB94530302 / man. date:11/99Constantly runs. I was told it needs a thermostat. I can't find anyone near me that can order it. Anyone else have this issue? If so, how did you fix it?