Can anyone tell me what is causing the yellow streaks on my ceiling? I have the unit pressure tested every year so there's no leaks. The roofing is fine, can't be causing leaks. I can't clean the streaks off either, does anyone know what I can use to remove the streaks? The ceiling panels appear to be vinyl. I have a 2014 Big Country and it is only happening in the living room. We don't smoke and rarely cook inside. We also keep the unit moisture free.