Loosing Water From The Fresh Water Tank
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Terawatt,
There will be no "repair" instructions, because we are not talking about damage. As has been discussed in this forum, there are different options to different applications relating to different uses and expectations of the tanks and the overflow vents.
In other words, this is not an issue for a number of our customers. It is a phenomenon that can occur because of the nature of the beast.
What we have tried to do through this forum is discuss possible remedies that will best fit individuals needs.
Some have added valves; some have rerouted their vent hoses so that they go up first, before coming back down (looping them over part of a steel floor truss), others have simply addressed the issue by monitoring their water levels prior to departure.
We hesitate putting valves on these overflow vent hoses because you and I both know that someone will forget to open a valve and will burst their tank.
Hope this helps.
ST
There will be no "repair" instructions, because we are not talking about damage. As has been discussed in this forum, there are different options to different applications relating to different uses and expectations of the tanks and the overflow vents.
In other words, this is not an issue for a number of our customers. It is a phenomenon that can occur because of the nature of the beast.
What we have tried to do through this forum is discuss possible remedies that will best fit individuals needs.
Some have added valves; some have rerouted their vent hoses so that they go up first, before coming back down (looping them over part of a steel floor truss), others have simply addressed the issue by monitoring their water levels prior to departure.
We hesitate putting valves on these overflow vent hoses because you and I both know that someone will forget to open a valve and will burst their tank.
Hope this helps.
ST
mrcomer
Past Ohio Chapter Leaders (Founding)
I see where Scott is coming from. Personally we do not do alot of dry camping so if anything we keep enough water in the tank in case we need to stop along the road to use the facilities or wash our hands etc. My preference is always to travel with as little fluid in all tanks as possible. In the case of some state parks I just wait till I get there and fill-er up.
timk and phranc - I appreciate your humor although it doesn't look as thou some others do. You made me chuckle. Thanks
timk and phranc - I appreciate your humor although it doesn't look as thou some others do. You made me chuckle. Thanks
Forrest Fetherolf
Senior Member
Water tanks draining
The factory could eliminate the tanks draining when full, traveling, or parked unlevel. Most all of us have diswashers in our home with a little thing on the sink called an air gap valve. Simply connect all 4 tank vents together with an air gap valve higher than the tank and run the drain line wherever makes you happy. You won't loose water unless you overfill the tank or park the rig upside down.
The factory could eliminate the tanks draining when full, traveling, or parked unlevel. Most all of us have diswashers in our home with a little thing on the sink called an air gap valve. Simply connect all 4 tank vents together with an air gap valve higher than the tank and run the drain line wherever makes you happy. You won't loose water unless you overfill the tank or park the rig upside down.
C
Chulinw
Guest
I have lost fresh water when I am backing into my drive way to get ready for a trip. I also like to travel with 2/3 of tank so I can make sure I have fresh water to use on the road. When I get to the campground I notice that 1/3 of the water has gone someplace besides using it to wash had and tolet use. I just keep read the form mabye some one will come up with a fix.
J
Jim_1899
Guest
I had this problem and after reading post here on the forum came up with a quick solution that has worked for me. The water starts to siphon and you can lose it all fast. I like to fill up with water especially when heading to a few camp grounds that I don't care for the water.
I went to Lowes in the plumbing department to buy a female hose end that fits the three fresh water tank drain hoses. Then I screw on three caps so that the water does not drain out. I can take a photo of them if you would like.
My wife's uncle had a huge expense after filling up his fresh water tank with a high pressure hose at a campground and in his RV the tank expanded and damaged his floor. I guess this is the reason that they installed the overflow drains. I can now leave with a full tank and not lose water. Most trips I fill up the water tank.
I went to Lowes in the plumbing department to buy a female hose end that fits the three fresh water tank drain hoses. Then I screw on three caps so that the water does not drain out. I can take a photo of them if you would like.
My wife's uncle had a huge expense after filling up his fresh water tank with a high pressure hose at a campground and in his RV the tank expanded and damaged his floor. I guess this is the reason that they installed the overflow drains. I can now leave with a full tank and not lose water. Most trips I fill up the water tank.
jpmorgan37
Well-known member
Jim;
Are you talking about a garden hose end? What size, 1/2 inch? Sounds like an easy fix.
John
Are you talking about a garden hose end? What size, 1/2 inch? Sounds like an easy fix.
John
timk
Well-known member
Chulinw said:
Chulinw
If you start out with just barley 2/3's of a tank, the water level in the tank has only to go down a very small bit, to get the 2/3 sender out of the water. Your guage will then say you only have 1/3, but in reality you may well have over half a tank, (or not). Or if your just a bit out of level the water level can get that sender dry as well.
There are a couple of fixes in this very thread, but if you do a search on "loosing" you will get a whole page of hits, with lots of good ideas.
TimK
sailorand
Past British Columbia Chapter Leader
Very simple to fix. Go to Home depot or Lowes, go to the plumbing isle and get 3 1/4 turn valves like the one that is on the FW tank drain. Install them on the 3 vents hoses and then close them. Just remember to open them when you fill the tank. Simple, easy, quick and not too expensive to fix if you can use a screwdriver
Uncle Rog
Well-known member
Howdy, never had the problem until now so I never checked out this thread. I had the broken tank fixed under warranty but much to my dismay I was still losing water pulling out of my (steep) driveway. Upon inspection, and happy to say, I realized the water was coming from the overflows. I am going with sailorand on this one. Never had this issue with other rigs, but it seems like an easy fix...............
mufflerman
Well-known member
Why not just run the vent up to the fill neck, on my cyclone there is even a spot to put a hose. The vent has to be higher then the tank, I plugged the vents on a trip and I didn't lose water out of the fill neck.
sailorand
Past British Columbia Chapter Leader
3 of my vents for the water tank come out underneath and by the wheels. Unless I take off the bottom coroplast to reroute them. Maybe much later I will take it off, but now now. It is really raining here and I have this aversion to laying in cold water for hours...
C
Chulinw
Guest
Going to get the valves and fix this like you said in other post about the problem of the water vents. I will get this fix and I am sure it will help out a lot. Like I was told make sure you have the vent valves open when filling the water tank in order to avoid any type of damage to the fresh water tank. This form has been very helpful to me and enjoy reading and I keep on learning new thinks to make life a lot easier. Tks for the help...
mufflerman
Well-known member
The valves will stop water from running out, But what a pain in the butt. I hope you are the only one filling the tank, or put a big sign by the fill neck!
M
meanderingman
Guest
Losing Fresh Water
It may be worse than you think. I have a 2006 Bighorn that is supposed to carry 63 gallons of fresh water. My fresh water tank was reading empty and sucking air into the water pump. I drained the tank of 3 gallons of water. After calibrating a garden water meter I filled the tank; it started overflowing from the vent hoses at 37.5 gallons. The tank gauge read 2/3 full. In addition to that, I am losing water when traveling, down to 1/3 tank. So I start out with 37.5 gallons and lose water while driving. This is a serious problem because I do a lot of dry camping. I'm going to have this checked out over the winter, will do a follow up when I get feedback from the service technicians.
FOLLOW UP--CORRECTION: Expert technician found the tank sagging, placed two bracing beams under the tank. The tank fills completely; technician measured the tank dimensions and calculated that it does indeed hold close to 63 gallons. Technician ran the vent hoses up into the water pump compartment and then out through the underbelly without vacuum breakers. The problem of losing water on the road is better, but one day I filled the tank until I saw the first drops of water at the vent hose drain--I then watched as 1/3 of the water siphoned onto the ground. I guess the next step is vacuum breakers.
FOLLOW UP: PROBLEM SOLVED--FINALLY
I had a problem of losing fresh water while traveling; I would start out with a full tank of 60 gallons and end up with 20 gallons at my destination. The original configuration of the 4 vent tubes had them going slightly upward from the top or sides of the tank, then down through the underbelly. Our first attempt to deal with the problem was to re-route the vent tubes further up into the water pump area, then back down through the underbelly. I seemed to be better, but I still lost fresh water.
The basic problem seems to be that the vent system is designed to siphon.
SIPHON DEFINITION; tube or pipe system consisting of two rigid or flexible legs in the form of an inverted J, used to convey a liquid from one vessel to another vessel at a lower level, over an intermediate point that is higher than either. When both legs of the siphon are full, the hydrostatic force due to gravity is larger on the longer leg, thus causing the liquid to move up the shorter leg, over the bend, and down the longer leg. The siphoning process can be started by filling a siphon with liquid before placing it into its operating location or by applying suction at the lower end after the tube is in position. Once started, the flow will continue until the liquid level in both vessels is equal, or until the level in the higher vessel falls below the inlet of the tube when air is sucked in and the siphoning action stops.
© 1993-2003 Microsoft Corporation. All rights reserved.
In this dysfunctional system, any time water begins to flow through the vent tubes it begins to siphon until the water level in the tank drops below the level of the vent tube outlet. Water flow and siphoning can begin with overfill, acceleration, deceleration, uphill, downhill, curves & turns, parking or driving on a slant, etc.
Here’s an example that I observed: I filled the tank until I noticed a tiny stream of water from one of the 4 vent tubes, then watched as the stream increased to full flow and continued for several minutes, dumping about 20 gallons. The siphoning must have partially collapsed the tank allowing more and more water to escape. Then, when a partial vacuum formed in the tank and the tube could not siphon any more water, the tube drained and filled with air, stopping the siphon.
Another example from before our first fix: I had driven 15 miles. When I made a turn off the road into a parking area, there was a circular path of spilled water on the gravel. I started out with a full tank, arrived with 1/3 tank.
DISCUSSION: my 1986 Alfa had a single vent tube about 2 inches in diameter that began at the top of the tank, went upward about two feet above the tank, and exited horizontally through the wall—it was possible for air and excess water to drain, but not possible to siphon.
SOLUTION: I cut the vent tubes off at their highest point, bound the tubes together with wire ties, and inserted 90 degree elbows pointing downward into a large funnel (the kind from an auto supply store that is used to add transmission fluid). A one inch plastic tube clamped to the funnel neck runs down through the underbelly to drain. This system can and does vent air and excess water, but it cannot siphon. Now I arrive at my destination with a full fresh water tank.
It may be worse than you think. I have a 2006 Bighorn that is supposed to carry 63 gallons of fresh water. My fresh water tank was reading empty and sucking air into the water pump. I drained the tank of 3 gallons of water. After calibrating a garden water meter I filled the tank; it started overflowing from the vent hoses at 37.5 gallons. The tank gauge read 2/3 full. In addition to that, I am losing water when traveling, down to 1/3 tank. So I start out with 37.5 gallons and lose water while driving. This is a serious problem because I do a lot of dry camping. I'm going to have this checked out over the winter, will do a follow up when I get feedback from the service technicians.
FOLLOW UP--CORRECTION: Expert technician found the tank sagging, placed two bracing beams under the tank. The tank fills completely; technician measured the tank dimensions and calculated that it does indeed hold close to 63 gallons. Technician ran the vent hoses up into the water pump compartment and then out through the underbelly without vacuum breakers. The problem of losing water on the road is better, but one day I filled the tank until I saw the first drops of water at the vent hose drain--I then watched as 1/3 of the water siphoned onto the ground. I guess the next step is vacuum breakers.
FOLLOW UP: PROBLEM SOLVED--FINALLY
I had a problem of losing fresh water while traveling; I would start out with a full tank of 60 gallons and end up with 20 gallons at my destination. The original configuration of the 4 vent tubes had them going slightly upward from the top or sides of the tank, then down through the underbelly. Our first attempt to deal with the problem was to re-route the vent tubes further up into the water pump area, then back down through the underbelly. I seemed to be better, but I still lost fresh water.
The basic problem seems to be that the vent system is designed to siphon.
SIPHON DEFINITION; tube or pipe system consisting of two rigid or flexible legs in the form of an inverted J, used to convey a liquid from one vessel to another vessel at a lower level, over an intermediate point that is higher than either. When both legs of the siphon are full, the hydrostatic force due to gravity is larger on the longer leg, thus causing the liquid to move up the shorter leg, over the bend, and down the longer leg. The siphoning process can be started by filling a siphon with liquid before placing it into its operating location or by applying suction at the lower end after the tube is in position. Once started, the flow will continue until the liquid level in both vessels is equal, or until the level in the higher vessel falls below the inlet of the tube when air is sucked in and the siphoning action stops.
© 1993-2003 Microsoft Corporation. All rights reserved.
In this dysfunctional system, any time water begins to flow through the vent tubes it begins to siphon until the water level in the tank drops below the level of the vent tube outlet. Water flow and siphoning can begin with overfill, acceleration, deceleration, uphill, downhill, curves & turns, parking or driving on a slant, etc.
Here’s an example that I observed: I filled the tank until I noticed a tiny stream of water from one of the 4 vent tubes, then watched as the stream increased to full flow and continued for several minutes, dumping about 20 gallons. The siphoning must have partially collapsed the tank allowing more and more water to escape. Then, when a partial vacuum formed in the tank and the tube could not siphon any more water, the tube drained and filled with air, stopping the siphon.
Another example from before our first fix: I had driven 15 miles. When I made a turn off the road into a parking area, there was a circular path of spilled water on the gravel. I started out with a full tank, arrived with 1/3 tank.
DISCUSSION: my 1986 Alfa had a single vent tube about 2 inches in diameter that began at the top of the tank, went upward about two feet above the tank, and exited horizontally through the wall—it was possible for air and excess water to drain, but not possible to siphon.
SOLUTION: I cut the vent tubes off at their highest point, bound the tubes together with wire ties, and inserted 90 degree elbows pointing downward into a large funnel (the kind from an auto supply store that is used to add transmission fluid). A one inch plastic tube clamped to the funnel neck runs down through the underbelly to drain. This system can and does vent air and excess water, but it cannot siphon. Now I arrive at my destination with a full fresh water tank.
Last edited:
Uncle Rog
Well-known member
MM, sounds like our rig only worse. We had a broken tank that would take a full load of h20 but would lose about 1/3 on the road. We have a 3600RL and am not sure if we have a 63 or 75 gallon tank, we have literature that says both. Any body know for sure? I bought a 5 gallon pail to drain into just to find out, I will post my results.....Happy New Year!
cdbMidland
Past Michigan Chapter Leader
Fresh water figures include the hot water heater. So a 12 gallon hot water heater leaves 63 gallons for the fresh water tank if your rating says 75 gallons.
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