Water pouring out of overflow hose

[bldngts2003]

Help. Water pouring out of overflow tubing of my fresh water tank immediately when I start to fill it with fresh water. What could’ve the problem??? ( not my low point drain but the short vertical tube that’s adjacent to tank fill area). Typically when I fill tank it overflows to that to show it’s full then I stop filling. Had trailer for 4 years and no problem till now

[WinnieView]

Is the tank full? What does the gauge read?

[mtdawg]

This is a problem with the fresh water tanks. If left unattended, it will drain half the contents out of the tank. The answer from Jayco is that once you are done filling the tank (water is coming out the overflow) then clamp/plug the hose(s). This will stop the siphoning. Just remember that once the tubes are clamped off, do not put any more water in the tank. I have never received and answer indicating there is a more permanent fix.

Jim

[bldngts2003]

Tank gauge read 2/3 ...so other people thinking I filled tank too fast with high pressure hose. Caused a vapor lock type of situation. Could that be?

[bldngts2003]

How do I clamp that short tube? I’ve never had this problem.

[Jagiven]

Personally, my first thought is a full tank. I would not fully trust the sensors. I would open your low point drain and confirm that it is empty. another option, as I see you have an open under belly, I have taken a very bright flashlight and placed it against the tank wall and slide it up and down, you can get a visual indication of the tank level.

Next try adding water a bit slower.

Next thing, inside the TT, find the compartment that has the gravity feed hose that flows through it. The overflow hose will be there too, take a quick look at it, it should come out of the top of the tank, and makes a vertical loop back down through the floor. Make sure everything looks right, and nothing is kinked. On my HTT, the gravity fill and the overflow are right next to each other.

[Johnny]

Originally Posted by bldngts2003

How do I clamp that short tube? I’ve never had this problem.

I have two tanks on my 26BH and I have two overflow tubes. I read about this problem and installed these on each overflow tube. They're dirt cheap and work really well. I went with the plastic versions so that there wasn't a lot of weight dangling on the tubes.

You've just gotta remember to open them before you start using water.

[mtdawg]

My tank has two tubes. One is a fairly rigid 1/2" hose which I blocked similar to what was described by Johnny. The other one is a flat tube described as a breather tube by the dealer. They claimed no water would come out of this tube. Not true. For that I just got a large alligator clip, fold the tube over and clamp it. Seems to work.

Jim

[dgodecke]

Originally Posted by bldngts2003

Help. Water pouring out of overflow tubing of my fresh water tank immediately when I start to fill it with fresh water. What could’ve the problem??? ( not my low point drain but the short vertical tube that’s adjacent to tank fill area). Typically when I fill tank it overflows to that to show it’s full then I stop filling. Had trailer for 4 years and no problem till now

I put a valve on the overflow, but not one that just hangs under the trailer to get hit and broken off.

I started with 1" plastic pipe. I used the electrical conduit kind, the gray pipe because it can be heated and bent to fit and I don't know if the white pipe can, but the white PVC fitting work on the gray pipe and they both use the same glue.

I glued a short nipple to an elbow, pushed the pipe up into the vent hose and clamped it in. I then pushed the whole thing back up as high as the elbow would allow. I took a 90 degree sweep and glued that into the elbow as as to bring the end in line with the trailer frame.

I then glued a pipe into the sweep and ran it forward. Heated the pipe with a heat blow gun and shaped it so it ran directly under an open space between the propane take holder and the front edge of that compartment. I cut out a section of the pipe at that point and glued in a ball valve. A short nipple out of the valve and another elbow pointed down and then secured the whole thing to the trailer frame with steel pipe hangers.

A screen was placed over the open elbow end and secured with a pair of tyi wraps, and some black paint to match the rest of the underside of the trailer and it good to go.

Now WORD OF CAUTION:
you MUST have the valve open when yo fill your freshwater tank!

The rest of the time the valve can be closed. As for me I just close the valve as part of my checklist when I am getting ready to move and open the valve the rest of the time. The screen is in place to keep bugs and stuff out of the system.

[dewey02]

Originally Posted by dgodecke

Now WORD OF CAUTION:
you MUST have the valve open when yo fill your freshwater tank!

The rest of the time the valve can be closed. As for me I just close the valve as part of my checklist when I am getting ready to move and open the valve the rest of the time. The screen is in place to keep bugs and stuff out of the system.

I'd suggest that you should also have your valve open when you are drawing water out of your FW tank. Those overflow tubes also act as vent tubes to let air in as the water gets pumped out.

[bdreinv]

I have heard that filling to fast can cause that problem too!Thanks good reminder.

[Isaacs]

Originally Posted by mtdawg

This is a problem with the fresh water tanks. If left unattended, it will drain half the contents out of the tank. The answer from Jayco is that once you are done filling the tank (water is coming out the overflow) then clamp/plug the hose(s). This will stop the siphoning. Just remember that once the tubes are clamped off, do not put any more water in the tank. I have never received and answer indicating there is a more permanent fix.

Jim

How can an overflow tube siphon? The end in the tank would have to have some sort of dip tube that was below water level for that to happen. Doesn't the overflow tube originate at the top of the tank? I suppose some water could slosh out of it during travel, but siphon?

[bldngts2003]

Thank you!! Great ideas will clamp that overflow and fill slower today and see what happens. Thank you!!

[dgodecke]

Originally Posted by dewey02

I'd suggest that you should also have your valve open when you are drawing water out of your FW tank. Those overflow tubes also act as vent tubes to let air in as the water gets pumped out.

My tank has a separate vent hose and overflow hose. I only close the overflow hose and only when I have a full tank and are on the road moving.

I can't say what all the rest of the 5th wheels have, or the TT, they may not have two hoses.

[dgodecke]

Originally Posted by Isaacs

How can an overflow tube siphon? The end in the tank would have to have some sort of dip tube that was below water level for that to happen. Doesn't the overflow tube originate at the top of the tank? I suppose some water could slosh out of it during travel, but siphon?

Mine sloshed out when I was traveling. Sometimes as much as half the tank even.

[pgartner]

Originally Posted by Johnny

I have two tanks on my 26BH

slightly off topic, i too have a 26bh with 2 tanks, but only have 1 fill inlet. (and 2 drain valves)

how are the 2 tanks connected? from a fill and water usage/pump point?

-Paul
(maiden voyage in t minus 10)

[RVhiker]

Originally Posted by pgartner

slightly off topic, i too have a 26bh with 2 tanks, but only have 1 fill inlet. (and 2 drain valves)

how are the 2 tanks connected? from a fill and water usage/pump point?

-Paul
(maiden voyage in t minus 10)

This thread may answer your question: Tank Plumbing Thread (clicky)

[Higgy]

Originally Posted by Isaacs

How can an overflow tube siphon? The end in the tank would have to have some sort of dip tube that was below water level for that to happen. Doesn't the overflow tube originate at the top of the tank? I suppose some water could slosh out of it during travel, but siphon?

My last trailer would siphon out the water once i filled it too but the new one seems ok. I sealed the last ones vent pipe like others have said and opened it up once at site. I think there must be a dip tube into the top of the tank otherwise a siphon wouldnt work like Isaacs said. Never had the drive to remove my underbelly to check. easier to stick a valve on the end of the pipe Just remember to open it to allow air in or you will end up with no water coming out. I dont think the little pump is strong enough to make the tank collapse though if you forget. Not that i would want to find out.

[tbwill]

Found this cheap plastic drip valve at Home Depot for $2.87 that works great - https://images.homedepot-static.com/...1s-64_1000.jpg