I have had this issue with cold air coming in around the pocket door since we bought the coach 6 yrs ago. Even asked about this on the forum, but no answers. I guess I was too lazy to pursue it. I did look a few times, but never seriously.
After the hurricane at Qsite, and another at Glamis, when the coach filled with heavy dust/sand, I realized I should look deeper. Finally while in Yuma for a month, I removed the pocket door and found the leak, but couldn't really do much because I forgot my screw gun (old timers), so I waited till I got home.
I did discover, that the cedar skin in the cabinet above the Washer Dryer comes out. But you have to remove the shelves. Fortunately it unscrews, and is not glued. It is also 1/2 the wall height, so it came out without removing the W/D.
So this is what I found. I believe sometime in it's life, someone complained about the refer not cooling. In the past, I have personally added foam to the back wall inside the refer cabinet to fill the space as a FT tech. This causes the air to be forced over the cooling fins, and out the top vent. But I have never seen this mod. We never did it at our store. Our refer works fine I might add, so not sure this made any difference. But it sure didn't hurt.
I believe what happened was, they cut this hole, to slide foam in on top of the refer to fill the space, forcing the hot air out the vent. Unfortunately, the foam really didn't stay glued. besides, it was 1" too small to fill the gap.
So I trimmed the foam to enlarge the hole, broke off the clothes rod backer (we don't have a clothes rods on that side) and pulled the loose foam out (the other one stayed glued to roof) and added a 1" piece, then slide them in with silicone on them. Why they didn't cover the hole is beyond me, as it allowed burning LP fumes to enter the coach. as you know, the cabinet is to be airtight to outside. So after a patch with scrap panel board, and some minor sealing up, we are all good.
I'm rarely on here, so email me if you have any questions. Pictures should explain everything.
Cheers
Chris
Well, glad you found the air leak, looks like a good fix. 🍺