Is this normal? If so, workarounds?

[nickbnick]

I have owned bumper pulls for years, but just bought my first 5th wheel - a new (2021) Jayco 27.5 RLTS. We did a trial 3 day camping a couple of hours from home this week and I am never going back to a bumper pull. But I did come back with questions, one regarding water.

The campground did not have site water so I filled up at the campground station. The manual says to watch the gauge inside while filling on the other side (inconvenient) but I did so. After I unhooked the hose, I noticed a small stream coming from what I assume is the overflow (a largish pipe with a black bag on it). As I watched, the stream stopped within seconds. I drove to my campsite on the level paved drive at about 5mph (lots of kids to watch out for). When I got out of my truck I noticed a water trail leading back down the road, so when I opened the camper I checked the fresh water level. 1/3 tank!

On the way out of the campground I did a test. I again filled the tank, waited until the stream from the overflow stopped, and gently pulled forward 50 feet and stopped. Water dumping out the overflow! After about 5 gallons (a guess of how much) flowed out, it fully stopped (after maybe 30 seconds). I drove slowly to the park entrance and stopped again. About 20 gallons dumped out of the overflow over a span of maybe 2 minutes, then stopped.

Questions:
1. Is the bigish pipe with the black bag on it the fresh water overfill pipe or vent pipe?
2. What is the small white pipe right next to it?
3. Is this normal? If so, what are the work-arounds as we do a lot of state and national forest boondocking?

Thanks to anyone that can help. Happy camping!

Pic of pipes and of camper in my yard attached.

[Grumpy]

No pics...

Tanks are know to siphon when traveling. Some have put a valve on the overflow to stop that from happening and there is a thread where others have built an anti-siphon system. If you go with the valve you have to remember to open it when filling and also open it when you get to your destination.

[nickbnick]

Oops. My pictures were over 5MB. Second try.

[nickbnick]

I have read threads on overfill valving, but never thought I would need one. I never thought of siphoning. I assumed the overflow would be at the high point of the tank and not go down inside it. Bummer. If I put a valve on does it need to be open when using water (does it also act as the tank vent)?

[Grumpy]

That larger pipe is new to me. I have never seen that used before and I assume that is the overflow with the other one being the tank drain. Apparently it is supposed to stop the siphon, but sounds like it doesn't work

[nickbnick]

I found the threads you referenced. They date back to 2013! So this has been a problem since then? Also, why would they need a tank drain if there is a low point drain?

[Grumpy]

Originally Posted by nickbnick

I found the threads you referenced. They date back to 2013! So this has been a problem since then? Also, why would they need a tank drain if there is a low point drain?

The tanks needs it's own drain as the low point drain only covers the inside piping.

[eow]

I have the two vent tubes on our FW as well and speculate that the large tube with rubber “shutoff” valve end is to prevent overfilling/ pressurizing the FW tank since the fill is a direct hookup not gravity fed as in the past TT we have had. The small tube is the usual vent, which is insufficient to prevent pressurizing the FW tank on a direct fill system.

I suspect your small vent tube may be plugged. And as a result, when you start moving with the larger vent tube still having water in it, the water starts syphoning from the tank.

This is all speculation, since I never had to deal with the issue you are experiencing. We have not lost water while travelling.

It is not normal to have FW tank water loss when travelling. It may be time to get the dealer to deal with it.

[nickbnick]

Sorry for so many questions, but I sure appreciate your help. If it is a tank drain, shouldn't there be a valve on it?

[eow]

There are three hoses that you should see from underneath from your FW tank. The large and small hoses in your pictures, and another small hose with a valve on it to drain the FW tank. I do not have the same model, but our drain valve is on the road side of the trailer, yours may be the same.

[Burchie70]

My Eagle Ht was draining water out of the tank every time we traveled with it. The bigger hose with the duckbill is the overflow pipe and the other one is the tank vent. You should also have a third line with a valve for draining the fresh water tank. Mine was siphoning out the tank vent pipe so I cut it up closer to the underbelly and put a 90 degree elbow and a section of pipe on to extend it out by the rear bumper. I put a ball valve on it so I can shut it off while traveling but I do open it once I get to where I’m going before using water. It stopped all the siphoning by 100%. I can post a picture of what I did if you want me to.

[JFlightRisk]

The fresh water tanks they install under campers are generally very very shallow. The connections to it are nipples spun-welded to it as high up the tank wall as they can get them, with the exception of the drain tube. There's no hose sticking into the tank to cause the same siphon effect as if you were siphoning gas from a car. The tanks are bulging some when they're filled to capacity, so any off level angle of the camper allows the water level to flow from the connections. We've got twin tanks under ours, and I bet they're not much more than 7" or 8" tall, but they span from frame rail to frame rail. A previous SOB trailer had a tank under the bed. That one never did that, but there was not much storage under there. I guess they changed the design to allow for storage, more water capacity, and a lower center of gravity

[ETCrockett]

The manual on my Pinnacle says to fill the tank until water starts coming out the overflow which is the bigger tube looks like a bicycle tube. When water starts coming out this tube, I'm guessing it will siphon off 5 gallons of water in a couple of minutes. Someone on this forum mentioned folding the tube and putting a large clip on it. I thought that is an easy and cheap trick so I tried it. I thought no way will it stay on while traveling. I have not lost the clip in over 5K miles and it works. I still have a full tank when I get to the campsite.

[Jim Smyth]

I have a spring clamp that I put on the end of that rubber one and I bought a sprinkler shut off valve that I put on the white one. I only use these 2 when I need to have a topped off water tank due to not being convenient to refill which is rare for me. We like full hook ups whenever possible. I have camped with another bud also with the same Jayco 5th wheel as we have. I have watched literally about 10-20 gallons come out of his overflow while he was traveling down the roads for at least the first hour of driving. Very poorly designed systems.


Here is a link to my pictures.


https://www.jaycoowners.com/forums/f...ube-60449.html

[TxLoser]

I’ve used large paper clips in the past. This last trip, folder the overflow over on itself and used a larger rubber band to keep it that way. Mine spits water when I first start to fill and then quits. After that, I just run it till it starts out the overflow. Throw on the rubber band or large paper clips and call it good. My HT did this and now my Eagle as well.

[OTTERCOMET]

We had the same problem with our 2017 Eagle HT 24.5 CKTS. Jayco has a dealer fix (ours was covered under warranty) As explained by our service manager, it involves increasing the length of the overflow drain with enough piping to make a large loop in the drain (and I think he said it was laid on top or the FE tank). The loop makes it harder for the sloshing water to start a siphon.

[BLTravels]

On our 28.5 we fill (with it turned to city fill then turn it back) until it runs out the smaller white tube without the shutoff valve (that is third tube). This tells us it if full. If moving to a site with any hills, it will come out of the larger, in our case black tube as an extra overflow exit point. We were told by the dealer it is an extra precaution for when the trailer is at an angle or traveling with a full tank and sloshing around. We never travel with a full tank or have lost more than a small amount when moving through a campground as mentioned.

[nickbnick]

Originally Posted by Burchie70

My Eagle Ht was draining water out of the tank every time we traveled with it. The bigger hose with the duckbill is the overflow pipe and the other one is the tank vent. You should also have a third line with a valve for draining the fresh water tank. Mine was siphoning out the tank vent pipe so I cut it up closer to the underbelly and put a 90 degree elbow and a section of pipe on to extend it out by the rear bumper. I put a ball valve on it so I can shut it off while traveling but I do open it once I get to where I’m going before using water. It stopped all the siphoning by 100%. I can post a picture of what I did if you want me to.

Pictures would be great! Interesting that yours drained from the vent and mine from the larger overfill pipe.

[nickbnick]

Thanks, everyone, for all the helpful advice.

[Geargrinder]

Lots of great insight. Here's one more. We have the same trailer. Had the same problem. To work around this, I had my son hold the water level gauge button down on the command panel in the trailer as I was filling the tank with water. When he said all of the indicator lights were lit (indicating the tank was full) I continued filling for maybe 5-10 seconds and stopped filling. Had I continued and filled the tank to the brim, the siphoning would have started, draining the tank.