[flybouy]

Originally Posted by FlyingAroundRV

This is a bit of a guess from an old floorlayer who used to do linoleum and tiles, but the "scorching" is not uniform around the register cutout. If it was burning from heat I would have kind of expected the "scorching" all the way round the vent. Is this vent near a sink? What I'm wondering is whether this could actually be water damage to the flooring. Some vinyl flooring has a paper like backing to make it a bit softer to walk on. Getting water in this will discolor the flooring. Also, I noticed that some of the areas where the flooring looks "scorched" the backing (the white stuff) looks thickened which also suggests watre damage. Has this area of floor ever been flooded with water, either because of a leak, or excess water when being mopped?
Edit:
I just went back and looked again at the second batch of pics. The thickening of the backing of the flooring, and also the flooring lifting and separating at the seam looks very much like water damage. These types of flooring are a very thin plastic layer over what is essentially a paper like composition. With the exposed edge around the vents, the flooring is susceptible to water wicking up through the backing paper. The water then attacks the inks used to print the patter on the layer under the vinyl topcoat.

These were my thoughts as well but I didn't want to be accused of being obnoxious when trying to help. After looking at the first photo on my desktop computer I could see what you observed as well as the raw wood against the duct in the upper left corner. The wood used in the framing of these campers make excellent kindling and for it to be apparently unchanged would have me suspect water damage or mold.