Water pouring from bottom of Tab when filling fresh water tank

WildRumpus

I was filling the freshwater tank in my 2016 CSS. I put a garden hose very snuggly against the filler hole, and the air vent hole above it was unobstructed. I had the hose on full blast and it seem to be filling just fine (Air was coming out of the little air hole and very little water was gurgling back through the filler hole). When it was full I turned off the hose and I could hear water pouring out from the bottom of the tab. As you can see in the photos there was a small waterfall of water pouring out.  It eventually stopped and I checked the fresh water level. It was at 81%. So I tried to fill the tank some more and the same thing happened. I waited until the water stopped pouring out of the bottom and checked the freshwater level. 81%. So my question is: is there some sort of line or hose that has come detached, perhaps due to excess pressure? Note: I am in Florida so I don’t think it’s a winterizing issue.

jkjenn

I cannot tell where on the T@b your photos are, but you likely have one of two things happening. Your freshwater tank is full and the overflow is working  as it should and the tank monitor is not accurate or you are not using a water pressure regulator and you popped the pressure relief valve on the Alde.

Sharon_is_SAM

I suspect your tank sensor is inaccurate (they do slip - maybe from your Florida heat).  Were you get 100% in the past?  

It is possible you have a loose connection where the fill hose meets the outer flange.  If your tank fills up, it can back up through the fill hose.  I would check to see if it leaks with your initial filling vs closer to the full tank level.

@jkjenn - what overflow?  Is there a separate overflow.  I am only familiar with the overflow that wets your shoes!

ScottG

The flexible fill hose is typically a slip on connection secured with a hose clamp. It's very possible this could work loose and leak water into the T@B innards when the tank is full enough to back up into the filler pipe. It would also probably leak some during filling.

As shown in Sharon's photo, in the S models this connection is buried in the depths behind the toilet and is not readily accessible. I'm thinking it's the same in the CS-S. If you are a good contortionist, you might be able to inspect it and maybe even reach it though the pump access hatch above the toilet.

Given the location of the leak, it could also be where the filler connects to the tank, or maybe even the tank itself. You will likely need to remove the plastic skirting under the camper to inspect those.

None of the fresh water tank elements are under pressure, so if the leak is high up you'll only see it when the tank is full above a certain level.

Good luck and please report back what you find.

WildRumpus

With my CSS, the plumbing is in the back (in the clamshell galley). That's nice, because I can see that there is no leaks there.  I like the theory that the tank is merely full (and the level meter is just not accurate).  Honestly, we almost never use the water tank because we don't boondock.  I just like to keep is full during hurricane season because we're on a well and live in FL. It's nice having 10 gallons of fresh water safely stored in the Tab!   I'll keep an eye on it, but as long as it's not leaking into an area of concern (i.e., the interior of the Tab), I guess it's not going to hurt anything. And considering the fact that it immediately pours out from the corrugated underbelly it must not be going inside, right?  If I removed the corrugated underbelly, would I be able to see the water tank and its connections? Is it very difficult to remove and reinstall that underbelly?  Thanks so much!

Ratkity

I know the fresh water tank can expand to hold almost 10% more water, then when you stop filling it, it'll spew it back out. There's a drain hole, but it'll go in the path of least resistance, i.e. back out the way it came in and could also spew under the corrugated board if the pressure caused the radiator hose connections to leak. My 2015 did not have an underbelly cover (those came later). I could watch the water tank overfill. Not only was my overflow/air tube way too small for the back-pressure of the overfilled tank, it also had a few spiders in it. Air could get in and out, but when it was all over, there were some dead spiders and a lot of water on the ground and my shoes.

jkjenn

Sharon_is_SAM said:

@jkjenn - what overflow?  Is there a separate overflow.  I am only familiar with the overflow that wets your shoes!

It might just be an oddity with my inside 5 gallon freshwater...but when I fill, if it goes over 5 gallons, it goes to an overflow tube and drains to the ground.

ScottG

The CS models may be configured a little differently, but the tanks are almost certainly going to be tucked into the same areas of the frame, underneath that corrugated underbelly. My 2015 doesn't have that feature, but I know other have removed and reinstalled theirs so maybe they can better advise.

I can't speak for the capability of your tank sensors (I don't have those either...) but the leak you describe (and show) does not seem like some normal overflow. It's your T@B, but I would be inclined to pursue a resolution.

BrianZ

Agree with @ScottG that it would be worth the minimal effort of removing a few screws to get a look at the tank and its inlet/outlet/drain pipes & pex connections (and doing so while adding water to see the actual location of leak), especially if there is reason to believe the leak is not coming from the corrugated input hose part. 
@WildRumpus, Scott has posted some nice photos of those tank connections before, viewed from underneath.  As I recall, the fresh water tank is located above the axle closer to the passenger side wheel, which I assume is what you've shown in the waterfall photo.  Not sure any of this would apply to your model though.

ScottG

Photos of the FW tank connections from my S model. You can see there are several connections that could be prone to leaking when the tank is full and backing up into the filler hose. Your CS may be arranged differently, but I'll bet a nickel the connections are the same.

tabiphile

You could zero in on what's happening with your leak and sensors by running some of the water back out of the tank...measure what is coming out and remove what should be half...then go back and fill it again and see what happens. The tank sensors are not super precise and neither is filling with a hose. 

ScottG

Given the original description, my suspicion is that the tank sensor issue is secondary to the leak. The tank is unable to remain filled above the level of the leak.

BrianZ

After looking at Scott's photos, it appears the fill hose is connected about halfway up the side of the tank, whereas the small air hose is connected about 80% up, a similar water level to where you said the leak stops.  So, if the leak is due to a disconnected hose, my guess is the small air vent hose.  However, a leaky pex pipe (blue) at the same level, just under the floor, could give the same results.

PS:  After the leak stops, when the water level settles at 81%, I would suggest turning on the water pump to see if it starts leaking again.  If so, that might indicate the leak is in the blue pex pipe feeding the pump and not the air tube or water fill tube.  If not, and the pump produces water at the faucet without air sputtering after a few minutes & no leaking, that would be more consistent with the pex pipes being ok.

mona

Had what seems an identical experience, right after I bought my new 2015. Mine was leaking out the vent. Had it repaired under warranty, and no problem since. 

Jeannie

jkjenn

jkjenn said:

Sharon_is_SAM said:

@jkjenn - what overflow?  Is there a separate overflow.  I am only familiar with the overflow that wets your shoes!

It might just be an oddity with my inside 5 gallon freshwater...but when I fill, if it goes over 5 gallons, it goes to an overflow tube and drains to the ground.

The blue outlet is where my freshwater overflow empties. Again, this would be true on early 2015 models and later, only. Sorry the focus isn't sharper. I was not in a good position to fine tune the shot. 😁