I was cleaning my 1402. Removed the baffles and noticed in the top left side running horizontal where the side section meets the top section there appears to be a small gap at the joint. Isthis by desisn or do I have an issue? I've also been having trouble getting the stove over 400 F. I use a magnetic thermo on top the stove in front of the blower exit. Originally it would get up yo 550 F, seems like performance has dropped off as well as burn time? It is only a few weeks old so I don't have alot of history, but something seems to have shanged.