FW tank maybe leaking?

[lakeside]

Sorry this is long, but I feel I need to explain in detail.

Packed for trip, hooked up, and filled FW tank for the first time for a 5 night dry camping trip. Heartland says FW capacity for Bighorn 3685RL is 72 gallons (12 in H2O heater and 60 in FW tank). H20 tank is full from a summer of being hooked up to city water.

I tested my S&B home water pump for flow rate and am pumping 6 gallons per minute out of the end of my white water hose. I pumped water for 10 minutes and checked the over flow and the tank gauge. Over flow dry, tank gauge reads 2/3 full. Pumped 2 more minutes, over flow dry, tank gauge still reads 2/3 full.

I turned the lever in the central control center from FILL TANK position to NORMAL position so that I could test water pump inside 5er. Everything worked perfect.

I forgot to turn lever back to FILL TANK position. I opened nozzle on water hose to continue filling FW tank for another minute and thought I could hear water flowing, but not really sure.

I realized the lever was in the wrong position so turned it to FILL TANK position and pumped water for 1 more minute. Over flow dry, tank gauge reads full.

I unhooked hose and started to drive up our driveway. DW says water is running out the back of the 5er????????????

I backed down to the level part of the driveway and watched clean clear water run out of a small hole just over the passenger side rear stabilizer jack for 5 minutes. The FW tank is located above and between the rear stabilizer jacks. Water stopped flowing and gauge reads 2/3 full.

We went camping (for 5 days). When we were setting up, the 5er was tipped toward the overflow side. Water ran out of the overflow until I got the 5er leveled up. We returned home with 1/3 tank of water. Everything was normal with absolutely NO more water leaking anywhere from the 5er.

It appears to me that the over flow line was plugged when I was filling the FW tank. Is that possible on a new unit?

Where might this water be coming from?

When I had the control center lever in the NORMAL position, is there any way for water to enter the FW tank or any other place near or around the FW tank (between the frame rails)?

I realize I need to open up the colorplast membrane and take a look at the FW tank and it’s connections, but I just wanted some input from experience folks.

Thanks.
Lakeside

 

[sengli]

I know when I fill ours, even to the 2/3 full reading....the water will run out of the overflows (over the rear tires on both sides) if the coach is tipped very much at all. It will continue to flow out seemingly forever sometimes too. If its running out of your coroplast, well thats not a normal thing. Have you ever removed the walls in the basement to see whats going on with the plumbing? I'd bet you could see where your water issue is when you filled FW tank with the selector in the wrong spot.

 

[danemayer]

If the internal check valve in the water pump has crud holding it partially open, then it's possible for water to flow backwards under pressure through the pump back into the fresh water tank.

 

[lakeside]

I kind of tap danced around my real concern in the O.P.

What happens when a FW tank is over filled if no water comes out of the overflow drain? Will the tank rupture or am I thinking too deep here?

Are there two overflow tubes on Bighorn FW tanks?

Lakeside

 

[danemayer]

If you have the 4-way Anderson Valve, the system is designed to accept water under pressure and overflow through the overflow drains when full. The purpose of the overflow drains is to prevent rupture.

With the gravity fill system, if you jam the hose into the opening in a way that blocks backflow when the tank is full, you could rupture the tank.

 

[lakeside]

OPer here.....

Please call me dummy!!!!!!!!!!!

I just went out and looked at the spot over the rear jack stabilizer where I saw the water pouring out. I found a 3/8” white plastic pipe nipple. Evidently when I saw the water pour out, I thought I had burst the FW tank. I had no clue that Heartland had installed two overflow vents on their Bighorn model. One vent installed on each side.
I was pumping water in on the driver side and watching the vent on that side. The FW tank was actually venting the over flow out of the vent on the passenger side.
DAH! Bozo……me….
Thanks folks for the help, again.
Lakeside

 

[danemayer]

Don't feel too bad. None of this is obvious and we all benefit from the collective input coming from thousands of forum members.

 

[hoefler]

In our Landmark, Heartland actually installed 3 overflows and 1 vent to the gravity fill.

 

[Lynn1130]

Even though you found the problem or what you thought was a problem let me give some insight as to what happens if you over fill the tanks. They expand, cracking the cheap, thin ply that is under them and expand the crossover which then leaks. If you are lucky (like me) you do not push the tanks out of shape and have to replace them. This lesson; do not turn the fill hose on more than about half way and what ever you do stay with it until the tanks fill because if you walk away. even for a minute, and more water is going in that can come out of the overfill lines, the tanks will expand. I also now have a water meter that attaches to the hose and shows me how much water has passed into the tank.

 

[lakeside]

Thanks for the note of caution. Where does one purchase a water meter as you mentioned in your post.

Lakeside

 

[Lynn1130]

This is what I got and it works great.

http://www.amazon.com/gp/product/B007NHS9M4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[lakeside]

Thanks. I will order one today.

Lakeside