inside water leak from rv roof a/c unit

I know it leaks when it rains but could it possibly be a blocked condensate drain? Worth a check

water leak

Moved from Forum Technical Support

Make sure the bolts have not been over tightened. Had one that wore a hole in the roof under the unit where you couldn't see it until the AC was pulled off. The slight movement going down the road combined with the AC touching the roof caused the hole. Chased this leak for several weeks until I pulled the AC and there it was. Patched the hole, put on a new gasket and used it for nine more years w/o any more problems.

Roof A/C Unit uses a 1" thick roof gasket.
4 bolts hold down A/C Unit to roof
Gasket gets compressed by half to properly seal.

Bolts can loosen over time. They should be 'snug' (20 INCH pounds).
Over tightening them can warp gasket/roof causing leaks.

Check this out...it's from one of the Forum members that really know his stuff.

Also make sure the drain holes in the pan are not plugged...

Roof AC Leaks....LINK

Thanks again. I will keep that in mind.

When you pull it off you may find that the sandwich design of the ceiling has collapsed or crushed together. The gasket is pretty firm rubber. I repaired a roof ac opening area and glued in small blocks of wood to give the area more support.

If this has been going on a while it may have messed up the plywood around there. If the membrane around that area is bubbled up or wavy it's damage to the plywood.

Thank you for your reply. I will work on replacing the gasket if it has one. The water leak pattern around the a/c vents appears to follow the slight tilt on the RV as it is parked. Thanks again.

X2 on tightening the four bolts but this may not explain the leaking around the vents unless the water ran along the ceiling to the nearest vents.