Does your stove exhaust vent have a louvered type vent outside the trailer or one of the lockable flapper style. Reason I ask is a few years ago I replaced my broken flapper style with the louvered style thinking it would be one less thing to remember(opening the vent) and whenever I got a heavy rain I would end up with an inch of water on my counter. It took me about 2 months of chasing before I finally traced it to the new vent. Water entered followed the small ducted portion into the inside wall an ran down the wall to the counter top.