Rooftop vents

[triplehorn]

I decided to order 360 siphon vent caps. I have a black, and two gray tanks so right I ordered 3. Much to my surprise I got up on the roof to install them and there are 4! Maybe one is for the washer drain to vent? (my best guess)

[MARK A]

There are "attic vents" up there as well that look the same except my attic ones are white.

Mark

[1retired06]

Attic vents are normally the mushroom vents, larger. One in front, one in back.

[BB_TX]

My attic vents are much larger diameter than my waste tank vents. All are white.

[triplehorn]

I have 2 mushroom vents, one in front a rear center. There are 4 other vents. They are all the cap style for tank vents. One is positioned about where the washer drain is. I think it may be a vent for the washer drain. Maybe someone knows for sure.
https://instagram.com/p/BVyAJ8XAwgN/