Isata 3 - Fresh Water Tank - Losing Water out the Overflow

[jneum525]

I don't dry camp often, but have noticed when I do, I typically end up at camp with 2/3 of a tank of fresh water (after having filled it completely full prior to leaving) with the loss coming from the sloshing and siphoniong etc. that takes place along the way, while driving.

I have seen a number of posts on this forum where folks have installed a manual valve or electric solenoid valve onto the overflow tube, but thus far, I have resisted doing that as I don't want to damage my fresh water tank by forgetting to open the valve before DW or others use the fresh water. It also may not be very convenient if installing a manual valve to climb underneath, every time we want to use the sink or bathroom along the way, while travelling.

Curious if anyone has tried rotating the fresh water tank overflow tube 180 degrees, so it sticks up above the tank a couple of inches?

I would think this would drastically cut down on the amount of water loss while travelling w/o adversely impacting the tank when filling it up. In doing so, it would probably make sense to add a filter of some kind to avoid something falling down the tube and contaminating the water tank.

Or does anyone have any other solutions to the water loss problem other than the installation of a valve of some kind?

Thanks

[Judge64]

The challenge is the Isata 3 is not a gravity fill tank. Those will have a vent at the fill port well above the tank.

You don't have a lot of options. You either go with the electronic valve like I did or you run the tube well over the height of the tank and route so it can still drain outside if you overfill the tank. I don't think an inch or two will matter much if you have a full tank and you are going down steep grades.


If you have a pre-departure and arrive check-list, it helps make sure the valve is open or closed when it should be.

[gremlin]

Couldn't you just connect the electric valve so that it was set opposite in condition to the pump. i.e. the valve is open whenever the pump is on as a safety? You could wire in an over-ride for when you fill it, but this would prevent you from trying to suck out of the tank while it was closed.

[Judge64]

Originally Posted by gremlin

Couldn't you just connect the electric valve so that it was set opposite in condition to the pump. i.e. the valve is open whenever the pump is on as a safety? You could wire in an over-ride for when you fill it, but this would prevent you from trying to suck out of the tank while it was closed.

I have used electric ball valves for several applications. They come normally open or normally closed.

Your idea is a good one but I see a couple challenges. First, you really want the valve open at most times. As the water heats and cools, there will be flexing as the temperature changes without a vent that may weaken the tank over time.

If you use a normally closed valve and wired it to the pump power, it could open when water starts pumping but it would close again when the pump stiops and you have to worry about expansion and contraction. Then you would need the manual override for filling and when the coach is sitting.

I installed a normally open valve with a wireless switch. Its open all the time and I just use a remote to close it while driving and the rest of the time I leave it open... if I am not going to have water. If I am going to have water or full hookups, I just leave it open and don't care if I lose some water.

[gremlin]

I don’t think it would open and shut with pumping. My pumps gets power when I turn it on and then pumps when the internal pressure switch says to pump. I’d wire it to the primary pump

[Judge64]

Originally Posted by gremlin

I don’t think it would open and shut with pumping. My pumps gets power when I turn it on and then pumps when the internal pressure switch says to pump. I’d wire it to the primary pump

If you wired it on the pump circuit, it would open when the pump power is turned on. When you turn the power to the pump off, it would close.

No need for it to open and close with each pump cycle. I use an IRVPWC2 Pump Controller and it could be wired to it in such a way it opens when pumping and closes when not pumping. This would address the OP's concerns too of something getting into the fresh water supply.

But I still contend it should be open all the time otherwise to prevent expansion and contraction and flexing of the tank.

[gremlin]

Using a volumetric expansion calculator I found on the internet (which means it's suspect of course https://www.engineeringtoolbox.com/v...ion-d_315.html) Shows that water expands around 1% heating from 50 to 100 degrees F so 80 gallons of water would take 80.8 gallons at that point, not sure if it's enough to do much given the flexibility of the tank, however your point is taken, and is why I suggested you wired an override as well, the idea of putting it on the pump circuit was the safety against collapsing the tank by pulling a vacuum through it, although I'd guess you'd just jam the pump.

[Judge64]

Its all a non-issue for me. I already have installed an electric ball valve and wireless switch so I am already manually controlling my vent.

[jneum525]

As mentioned above, not quite ready yet to install a valve (electric Or manual) on the fresh tank overflow tubing, but appreciate the feedback.

I decided to give my idea a try of routing the overflow higher above the tank. . Went to Home Depot and got a few 1/2” elbows And a section of half-inch tubing. Rotated the Overflow tube elbow for the down spout 180° and ran it up to the frame rail and then back down using a couple of 90° elbows. I was able to raise it a little over 5 inches above the tank.

Hopefully, this will make a difference in keeping the water from sloshing out Of the freshwater tank during travel, But I really won’t know until our next trip.

I Will report back after my next trip and let everyone know if my tank stayed full during the travel. Hoping this will be a good solution, and won’t have to worry about remembering to open or close a valve during travel when using the water pump and when I get to my destination.

I uploaded some pictures of the before and after.

[Tucson Steve]

Interesting. I'm anxious to hear how it works. When testing you should also intentionally overfill the tank to make sure it's still doing its job.

[jneum525]

Originally Posted by Tucson Steve

Interesting. I'm anxious to hear how it works. When testing you should also intentionally overfill the tank to make sure it's still doing its job.

Yes, I am very interested as well to find out if my modification eliminates or greatly reduces the amount of fresh water that I lose, while traveling to my destination.

As for the intentional overfilling, I already did that. As soon as I was done, I filled up the tank until it was full and water was coming out of the overflow just as it used to when the tank was full.

[Judge64]

That may work out just fine for you. Nice work.

Unfortunately this is not an option for the 24FWSFX Freedom Edition.

I have the 50 gallon water tank and it is under the bed. The vent / overflow goes straight through the floor. There is no room above the tank to raise the vent / overflow since the bed is over top of it.

The electric ball valve was the best way to go for my configuration.

[jneum525]

Originally Posted by Judge64

That may work out just fine for you. Nice work.

Unfortunately this is not an option for the 24FWSFX Freedom Edition.

I have the 50 gallon water tank and it is under the bed. The vent / overflow goes straight through the floor. There is no room above the tank to raise the vent / overflow since the bed is over top of it.

The electric ball valve was the best way to go for my configuration.

Thanks. Time will tell I guess if my modification works. I certainly don’t think it can hurt anything. Hopefully it will solve the problem without the need for a valve.

I am a little envious of that 50 gallon water tank of yours. I guess a bigger tank is the benefit of reducing weight by eliminating the generator and propane, etc.

Not that familiar with the freedom edition although very intrigued by what I do know. Does that mean that you don’t have any storage under the bed at all?

[Judge64]

Originally Posted by jneum525

Thanks. Time will tell I guess if my modification works. I certainly don’t think it can hurt anything. Hopefully it will solve the problem without the need for a valve.

I am a little envious of that 50 gallon water tank of yours. I guess a bigger tank is the benefit of reducing weight by eliminating the generator and propane, etc.

Not that familiar with the freedom edition although very intrigued by what I do know. Does that mean that you don’t have any storage under the bed at all?

No real storage under the bed..... but I have installed my Starlink Router there and a few other gadgets.


Moving from a Super C with 65 gallons of fresh water to the Freedom Edition with 50 gallons made downsizing a bit easier.

But I have lost as much as 10 gallons of water through that vent / overflow going down steep grades. Not a big deal when we have full hookups but when we are camping without water, that is a significant loss. So that is why I did the electric valve.