No Spam Please wrote:
5 months ago I purchased a Pella Proline patio door and it is frosting
up along the seal edge on cold days below 15. This door is about 4
months old.
I was wondering if others had this same problem with this patio door ?

What do you mean by "frosting up"? The best windows in the world get
frost on them if the inside humidity compared to the outside temperature
is high enough.