I have posted this before but it may have got lost due spell mangle mistaking truma and trump. If you have a side exiting chimney on your van water vapour condenses and dribbles down the side of your van, this can stain and is a right swine to rectify. Simple fix is to attach a clothes peg to the bottom lip, the water then runs down down the peg not your van. This is especially useful when using boiler in the depths of winter no more icicles down the side of the van.