Fresh water overflow tube question

[bankr63]

Here is how mine is setup on an older 19H than yours:
https://www.jaycoowners.com/forums/m...ture11574.html


This is in the cabinet below the closet where the pump is located (background). As you can see, the floor is cut out down to the tank top. The large hose is the fill tube, and the small hose is the overflow that feeds back down through the floor in front of the tank. This comes out pretty much where you show your hose, making me hopeful that they haven't changed the design much.
I am suggesting that you tap into the overflow hose at the top of the U using a shutoff valve like the ones you see in the other lines in the picture.
BTW - no judgement on our housekeeping please. I open this cabinet a couple of times a year and it does not represent the general state of housekeeping in our TT. Already on my to do list for the next general cleaning.
ETA: There is an image tag there to a photo in my gallery. not sure why the image isn't displaying, but added the direct link to the photo here on JOF

[Barbmitc]

Ours hangs down below our Jayco Eagle and we simply take one of those black clips that you use to hold a bunch of sheets of paper together and clip it on the end of the hose as soon as it starts overflowing and that eliminates the problem

[Darkzell]

I went a little over board on my solution to the siphoning. I added a gravity fill to the back of the trailer to act as a air vent. Worked great so far with no loss of water and never have to worry about collapsing the tank. There was a pipe from the outdoor kitchen tank that ran to the back so I just extended the hoses and followed it up. Hardest thing was cutting a hole in the trailer and getting that blasted black underbody plastic covering back up.

[sullivanclan]

Do NOT block that over flow tube from the water tank! I did that with a valve and forgot to open it during a water fill which had a lot of air in it at a campground. Almost damaged the floor and walls around the water tank. That air in the water tank MUST escape somewhere.

[TnHiker]

Originally Posted by sullivanclan

Do NOT block that over flow tube from the water tank! I did that with a valve and forgot to open it during a water fill which had a lot of air in it at a campground. Almost damaged the floor and walls around the water tank. That air in the water tank MUST escape somewhere.

What sullivanclan said!

When the water starts coming out the "overflow" thus the name, the tank is full. The air has to be displaced when filling and when you are pumping water out the air has to to come back in, if it can't the tank might collapse. On my camper it has a pressure city/tank fill valve which makes it critical. It is okay to put a shutoff valve on the overflow to close while traveling but you have to have it open to fill and pump out. My memory is not that good enough anymore for me to take that chance. Camp happy and God Bless!

[JCM]

Here is my shut off. Open it when filling till overflow. Shut it off while traveling to stop the water loss BUT open it when parked. After the first few days - leave it open. Can save you 1/4 of your tank. BUT put a sign on the fill site warning to open the valve. If not could blow up your tank.

[Duke4857]

I fail to see why Jayco does not use the vent that is incorporated in the filler cap. On our 2016 TT they blocked off the vent on the filler cap and vented the tank to the ground.

[Cshenberger]

I also don't understand why jayco doesn't use the vent that's part of the filler. We have two vent tubes so I took a piece of tin and bought some low point drain valves. I put them out to the edge of the camper where they are easy to get to.

I plan to integrate them to the built in vent at the end of the season when I have more time. Right now more interested in just camping.

[cfarrar]

Originally Posted by Javin

I have been meaning to address this issue for a while. When ever we fill our fresh water tank, before its full the over flow tube underneath the trailer starts gushing water. To make matters worse I had to back into a steep incline which seemed to make more water come out of the overflow tube. A guy who was in line to fill told me he capped his overflow tube to prevent this from happening.

Is it ok to cap this tube in order to prevent a days worth of water from leaking out after filling the tank? If so what would you use to cap it? Not sure if it is left uncapped for a reason, perhaps air flow? Or did they just forget to cap mine??

If you look at your fill cap at about the 11 o'clock position there is a vent that should be connected to the water tank vent tube, I had the same problem with siphoning the water, changed the vent tube, end of broblem

[Duke4857]

Jayco sealed the vent with some goop and cut the hose vent tube connection off of on our trailer. I would have to replace the filler in order to hook up the vent to the filler where I think it should be. Thinking about replacement.

https://www.amazon.com/Valterra-BLAC...%2C263&sr=8-15

[Javin]

Originally Posted by Barbmitc

Ours hangs down below our Jayco Eagle and we simply take one of those black clips that you use to hold a bunch of sheets of paper together and clip it on the end of the hose as soon as it starts overflowing and that eliminates the problem

Considering I don't have much time till our next trip I am going to try this clip trick and see how it works for us. Thanks to everyone for posting their own hacks. You would think Jayco would have implemented some of these ideas by now.

[cfarrar]

Originally Posted by Duke4857

Jayco sealed the vent with some goop and cut the hose vent tube connection off of on our trailer. I would have to replace the filler in order to hook up the vent to the filler where I think it should be. Thinking about replacement.

https://www.amazon.com/Valterra-BLAC...%2C263&sr=8-15

I replaced my fill, easy job

[Javin]

I tried the black clip trick but unfortunately our tube is too ridged to compress fully to stop the water flow. Will have to try something else. Does anyone know of a plumbing fitting that could be placed inside the end of the tube in order to cap it when filling?

[JCM]

Try a simple old fashioned cork. Put a string through it so it doesn't get stuck in the pipe.

[Gazoo]

Why is this an issue? So some water spills out... I’m not sure I follow the need to fix it. I just filled mine up 15 mins ago, I lost maybe a gallon?

[madmaxmutt]

Because if we let it flow, we end up at 1/3 tank.

[Gazoo]

Yes then u do have an issue. I lose a gallon.

[Cshenberger]

Gazoo,

Depends on your camper and how they are connected. I lose about 3-4 gallons if injust let it run. But if we fill at home and leave while it's running we might lose 20-30 gallons before the siphon gets broken

[Zenar]

I have 16XRB and I don't have this issue. Maybe you need to leave the tank fill cap open for a bit?

[JimD]

It all depends on what rig you have. Many, like mine, have a couple of overflow hoses hanging down. I would lose 1/3 of a tank driving to my off road spot. Not good when you have limited water.

To fill your tank you pump water in until it starts flowing out the hoses. Most times when you stop filling the water flow out the hoses will come to a stop. But as you drive it seems to suck additional water out. I also found out that if I filled the tank at full pressure, the water would start out the hoses and NOT stop flowing for an extended period of time really draining the tank.

Breaking the siphon is a must. I extended my hoses up high and installed shut off valves. Since the hoses are high I really don't need the valves but have them just in case.