Purchased new 20 cu. ft. freezer two days ago. Plugged in for 12 hours before loading with solidly frozen food yesterday a.m. Closed door after loading and has remained closed thereafter. Unit is located in my kitchen with proper space allowed all around installation. The unit has run non-stop for 24 hours now (I was working in the kitchen all night). Is this normal or could there be a problem with this unit? Thank You!