Water Coming out of Underbelly

Hoping someone has had this issue and found the cause. After breaking camp from a weeks stay, first stop at entrance to park and water pours out of underbelly to the front. This has happened twice and dealer or myself have been unable to find any leak anywhere in the plumbing. Filled all tanks and drained, checked valves, no leaks. Checked all shower, sink, drain connections under the floor and none found. Checked all UDC connections, no leaks. Wondering if this could be coming from the roof somehow and getting into the underbelly. No water in basement at all. On both occasions, there has been storm on the day before leaving the park. Where on top could this water be coming from and how does it get to the underbelly? Any help appreciated.

Just a wild guess...and I am assuming you mean fresh water, not grey...
If you were hoooked up to campground water there is a valve that is supposed to keep water from going into the fresh water tank. If this valve is not working properly water can enter the fresh water tank.
Drop the underbelly at least to the point where you can see and check to make sure the there is no water coming through the line that the pump uses to draw water from the tank.
If no leaks there I would also check the the vent or fill tube coming off the fresh water tank. As the tank fills up and the vent or fill line is leaking either at the tank or the line itself. the belly will also fill up.

If you dont want to drop the belly here is another way to check and make sure the check valve is good or bad. When you get home, hook up the city water and turn it on. Open the fresh water tank drain and leave it on for a day. You may also want to put a bucket under the drain. If you get water in the bucket out of the drain, you at least know where to start looking and what the cause is.

I filled my fresh tank in less than a week because of this. With my water hooked up and drain open I will have a steady drip out of the drain. Not everytime we go though. It kind of comes and goes for whatever reason.
Hope this helps a little.

Charlie, I don't know what is causing your water in the belly, but it could be a number of different things.
I know that on ours, if the kitchen tank gets full, I get water running out of the bottom. I think the problem is that the vent pipe has lost its seal. No big deal, and an easy fix.
I just have not been ambitious enough to dive into the repair, but I know I will have to tackle it this week. Been like that for at least a year.
My temporaty fix is to drain the tanks more often so it doesn't have a chance to fill up.
So, do you think one of your tanks gets full and maybe have the same problem as I do. Can you tell if it's grey water or fresh? Maybe take a jar and collect some to check it out.
Another thing is, have you checked on the roof and looked to be certain everything looks sealed up?
Please let us know if you find the culprit.

Peace
Dave

I did drop the underbelly yesterday in the front section where water was coming from. We have not used the freshwater tank other than to check it during the PDI. We always use city water connection. I will try the bucket method though and see what happens. Thanks

Our experience has been that occasionally when towing in rain or on wet roads, the truck tires spray water on the front of the 5er at the bottom. These underbellys are not completely water tight (as evidenced by it "pouring out of the underbelly to the front"). If it can get out, it can get in!! Sometimes water gets into the belly and will later come out when the attitude of the trailer changes. We had it happen at a dump station when we used the leveling system to "tilt" the trailer toward the dump...a gallon or two of water came out of the belly.

If you find no other cause, I wouldn't sweat it too much....

We had an issue on our North Trail 21FBS - when we were in the process of filling the fresh water tank we had an issue with water streaming out of the the underbelly - once the tank was full however, no leaking. Dealer found the problem - a faulty seal on the fill tube where it enters the fresh water tank.

I've got water in the underbelly issues also. First 400 miles with a new Grand Canyon, stopped on a quiet freeway entrance so was tipped some to the right. To my dismay water poured out of the underbelly on the right side. Grey 1 was 1/3 full, only maybe 15 gallons at most fresh tank. Haven't had a chance to drop any of the underbelly to see if it is still wet but am going to soon. Had pulled in pretty heavy rain the night before so actually now I am hoping maybe that was it from reading these posts. I've been worried about a tank seal or crack. I hate the thought of a soaked underbelly! We had a 40' King of the Road they had stapled through a water line so it was misting in the underbelly until it sagged it enough to be noticeable, a real nightmare. When I saw this I was alone and tired at 6:00 AM and I thought oh not again!

Thanks to all who responded. I poked a hole in the lowest portion of the underbelly and will watch it more closely. Not gonna worry to much about it as long as it is not in the house.

We had a grey water plumbing leak. The drip was back by the axles.

I would suggest you empty all holding tanks. And then get short piece of water hose (3') and custom make a device that can be hooked to a air compressor and charge the water system with Air. That was done prior to our PDI, and if there is a leak air doesn't make a mess. Be sure the compressor is set at 50 lbs pressure. As for the water I would for sure try to get it dry, and or replace whats wet, remember mold is a killer. The device can be found at Wally World very in-expensive, and the air hose fits it perfect. Lots of people blow out the water lines instead of pouring in RV anti-freeze for winterizing. Good Luck. GBY....

I go under the trailer and lift the underbelly and water just pours out the now lower edges. I get the water while driving in the rain.
I have not driven in the rain for the least 6 month and I have no water in the underbelly now.

Got under trailer with drill and drive socket. Dropped the bolts along the axles and pushed up on the low points, still wet. Also wet in front under the 5th wheel. It is either wet road or grey 1 tank issue. With an apparent wet underbelly issues from this forum, maybe it shouldn't be a one piece underbelly?! Would be much easier to drop and dry out, which is what bothers me the most, a new rig now wet. Hopefully the insulation used under the foam core is anti everything bad that happens when stuff gets wet. If they do get wet from the road they should be sealed with foam or something along the axles and probably the front, I do have a big gap between two bolts at the front. They can't expect us to just not pull on wet roads! They need to deal with it in someway and no transporter stops for wet roads. Makes me wonder how many rigs people unknowingly take possession of with an already soaked underbelly. I don't mean to be seemingly just complaining on this forum but that is what it's for and especially with a new unit I am trying to get things worked out. I think this is my 13th (Oh Oh) unit counting the others I currently own, two of which were custom built. I am still seeing good things with Heartland for a mass manufacturer, but also see postings about quality control issues since getting larger and busier. There are things with this unit a little sloppy, like my bedroom door won't close and also won't hook back properly because the board it hooks to under the carpet is either loose or cracked. And when my printer was plugged in to the outlet under the desk, the outlet had been overcut and shoved right through into the other cabinet.
But now back to the wet underbelly, I think it should be dropped and dried out and thoroughly checked over for actual problems. A new Heartland dealer of 2 months says he can't get it in for 2-3 weeks and I will be long gone by then, haven't checked on a dealer near my next stop yet but I don't expect one to be near. Seems to me he should be anxious to get a unit in to see what they are dealing with but guess not. Was pretty dead in there at the time too.

On a previous trailer (s.o.b.) I found that an "underbelly leak" was actually water in the core of the coroplast underbelly cover. The holes in the coroplast filled from road water and it would drain out one side when the trailer was parked on an angle. It appeared as if water was coming from inside the underbelly however. However it was dry inside.

Hi guys, we are one of the those who get water in the underbelly - we believe it is from driving in the rain. We've had the bottom off and replaced a couple of times because the weight of the water and wet insulation stretches the coroplast.

Now we have removed the fiberglas insulation completely, and were told that the new ones don't use it anymore. I don't know if that is true or not.

We are contemplating a plan to remove all the coroplast and foam that was used to "seal" it and do our best to insulate the underside of the coach floor with styroboard. Then we want to put interlocking aluminum sheet panels (about 2 foot widths) in place of the coroplast. This would give us access if we need to get into the belly in the future.

Has anyone tried something like this or have some suggestions of other materials or techniques we should consider?

Has anyone tried