2017 wildwood clean water tank loosing water

[micsol84]

I fill my clean water tank full. And when I get to my.destination I'm down to 1/3 of a tank. Why. The drain valve is closed. And I don't see.any leaks. Is it all sloshing out the overflow while traveling? I would think id be able to fill it and still have a gull tank when I get to where I'm going

[Mr. Dan]

Originally Posted by micsol84

I fill my clean water tank full. And when I get to my.destination I'm down to 1/3 of a tank. Why. The drain valve is closed. And I don't see.any leaks. Is it all sloshing out the overflow while traveling? I would think id be able to fill it and still have a gull tank when I get to where I'm going

Apparently, it siphons out through the overflow/vent. You might do a search for 'siphon' and find what had been written in the past.

[rockfordroo]

Explanation:
The vent line comes off the side of the tank (really should be off the top, but....). It goes UP and then turns and comes down (usually). This creates an upside down loop. When you go around a turn, the water sloshes up into the loop. Once it hits the top and goes down the other side, that creates the siphon and it will drain water from your tank until the level drops below where the vent is attached to the tank.

You have two potential fixes:
The best, if possible, it to reroute the vent line so it doesn't go back down. If you do this make sure that if water were to come out of it by overfilling, it has somewhere to go besides into your rig.

The second option, as some folks have done, is to install a closed valve in the vent line to prevent the siphoning. If you do this, you must be sure to re-open the valve when you're using and/or filling the tank. If not, you may blow up or collapse the tank.

[micsol84]

Do they make anything like an anti siphon valve that would allow venting and overflow without spilling?

[kzoromski]

[kzoromski]

I had same issue. Water sloshing comes out vent lines. Installed 1 on vent line on each side. I just close the valves while driving. Works and pretty cheap fix

[rockfordroo]

Originally Posted by rockfordroo

Explanation:
The vent line comes off the side of the tank (really should be off the top, but....). It goes UP and then turns and comes down (usually). This creates an upside down loop. When you go around a turn, the water sloshes up into the loop. Once it hits the top and goes down the other side, that creates the siphon and it will drain water from your tank until the level drops below where the vent is attached to the tank.

You have two potential fixes:
The best, if possible, it to reroute the vent line so it doesn't go back down. If you do this make sure that if water were to come out of it by overfilling, it has somewhere to go besides into your rig.

The second option, as some folks have done, is to install a closed valve in the vent line to prevent the siphoning. If you do this, you must be sure to re-open the valve when you're using and/or filling the tank. If not, you may blow up or collapse the tank.

I was a bit off when I wrote this one. I should have said, route the loop high enough so the water can't slosh that high. But that usually means it will no longer loop back down. The truly ideal solution is a vent line long enough that you can raise the loop very high, but the bottom is still down under the rig.

[Jeff from Burlington Ont]

I had something similar on my 2017 Wildwood.. AS I filled the FW tank, it as soon as I got to 2/3 full, it would start to drain out the overflow. I had to cut the belly pan open, chip away some spray foam and re-route the overflow tube above the height of the tank and then back down again. there was enough slack in the pipe for me to get it done.

I then taped up the belly pan..

[micsol84]

Since building up pressure or vacuum in the tank is a major concern with putting a valve in the vent and leaving it closed. Would traveling with it closed be a bad idea too? With elevation changes and what not. I live Colorado and know very well the effect of elevation on sealed items (exploded bags of chips and shampoo bottles) etc. Changes from 5-11000ft are common

[rockfordroo]

Originally Posted by micsol84

Since building up pressure or vacuum in the tank is a major concern with putting a valve in the vent and leaving it closed. Would traveling with it closed be a bad idea too? With elevation changes and what not. I live Colorado and know very well the effect of elevation on sealed items (exploded bags of chips and shampoo bottles) etc. Changes from 5-11000ft are common

The pressure change from elevation is not worth worrying about.

Pressure at sea level is 14.70 psi. According to this calculator, at 11,000 ft it's 14.69 psi. Essentially no change.

https://www.mide.com/pages/air-press...ude-calculator

(Use the calculator in the blue box.)

[micsol84]

Originally Posted by rockfordroo

The pressure change from elevation is not worth worrying about.

Pressure at sea level is 14.70 psi. According to this calculator, at 11,000 ft it's 14.69 psi. Essentially no change.

https://www.mide.com/pages/air-press...ude-calculator

(Use the calculator in the blue box.)

Looking at the link you provided that's actually not correct. If you scroll past the blue box it will give a chart of atmospheric pressures at altitude. You are correct at sea level atmospheric pressure is 14.7. But at 10000ft it is only 10.1. In fact between 5 &10000ft it drops from over 12. And while an almost 5 psi drop doesn't seem like much that drop over a surface the size of a water tank could in my mind be enough to potentially cause the tank to deform either collapse or other. But I could be wrong on that that's why I'm asking

[rockfordroo]

Originally Posted by micsol84

Looking at the link you provided that's actually not correct. If you scroll past the blue box it will give a chart of atmospheric pressures at altitude. You are correct at sea level atmospheric pressure is 14.7. But at 10000ft it is only 10.1. In fact between 5 &10000ft it drops from over 12. And while an almost 5 psi drop doesn't seem like much that drop over a surface the size of a water tank could in my mind be enough to potentially cause the tank to deform either collapse or other. But I could be wrong on that that's why I'm asking

You're right - that 0.01 DID seem a bit small; I should have known better and questioned it. Wonder what's wrong with their "calculator?"

Yes, 5 psi over a tank top or bottom is a lot. A 2 x 6 ft tank would be 24 x 72 = 1728 sq in, 5 lb/sq in x 1728 sq in = 8,640 lbs. Quite a bit.

Personally, I'd add hose length to the vent hose and get the loop above the tank rather than going the valve route.

[kzoromski]

I would agree. If I lived in an area with elevation changes that were significant I wouldn't use valves either I guess. I really don't leave Wisconsin though and they seem to work fine. Good info though

[mkosu04]

X2 on adding the valve on the overflow. Make sure its open once you start running the pump.

The other solution (more work, but much more eloquent) is to dig out that hose and route it up to the built-in vent on the water fill port that Forest River was too LAZY to use.

As far as pressure changes - it is not a concern for 2 reasons.
1 - the water tank is flexible and a large cube.
2 - water is barely compressible so a full water tank won't change volume.

The examples of shampoo leaking - its a cheap valve that leaks easy, and its a small cylinder shaped container so it has very little flex. And I'm guessing it was at least 1/2 empty and you were probably flying in an airplane and not driving down a mountain.

[rockfordroo]

Originally Posted by mkosu04

X2 on adding the valve on the overflow. Make sure its open once you start running the pump.

The other solution (more work, but much more eloquent) is to dig out that hose and route it up to the built-in vent on the water fill port that Forest River was too LAZY to use.

As far as pressure changes - it is not a concern for 2 reasons.
1 - the water tank is flexible and a large cube.
2 - water is barely compressible so a full water tank won't change volume.

The examples of shampoo leaking - its a cheap valve that leaks easy, and its a small cylinder shaped container so it has very little flex. And I'm guessing it was at least 1/2 empty and you were probably flying in an airplane and not driving down a mountain.

Provided it's FULL. If it's not full, you could have an issue.

[kzoromski]

After thinking about this. The tank is not sealed. The fill tube is a garden hose connection with a dust cover snapped on it.

[kzoromski]

[micsol84]

Originally Posted by kzoromski

Attachment 141246

My fresh water connection looks different it.is a twist on cap. Which I believe makes more.of an airtight connection but I don't know

[kzoromski]

I believe your right. This is all mine has. Which isn't the best for adding water when using a jug/container. I have to pump it in with a small pump. I works though just an extra step

[geoff270ssf]

We had a similar thing happen with our Georgetown 270SSF: filled FW tank to the top then drove 1/8 mile to our campsite. Noticed water pouring out of the overflow (which is tapped into the TOP of the FW tank). Levelled the rig, came back and water was STILL pouring out. Observed water level still full, then the Dear Wife turned on the pump and ran some water into the sink and I heard a "GOOSH" and watched the FW tank level drop instantly to 1/3. And no, I had not been drinking...

What kept that water level so high when so much water had drained? Tank distortion couldn't account for that much lost volume.