I think I need to install the Jotul outside air kit, last year I had issues maintaining a good burn. Our house is new and really airtight. Cracking open a window near the stove always fixed the issue, but I can't keep a window open all winter. I was looking into the Jotul outside air kit, I purchased the adapter 154335. It seems to be a couple of inches too small for the inlet on the bottom of the F600. Even with the tabs bent out, it can easily fall out of the bottom of the stove. The paperwork with the adapter lists both part numbers, 154333 and 154335, so maybe I messed up and ordered the wrong one. The problem is, I can't seem to find anyone online selling the larger one. I found one retailer that lists the dimensions for the 154333, and it's the same as 154335. Anyone have any idea if that's just how it is, or is there actually a different, larger adapter for the F600?