Surfside
California
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Joined: 08/02/2008
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I just bought a used 2007 National Surfside. Problem filling the water tank. It will not fill up. when you fill it till it runs out the over flow then it keeps running out till the tank is 1/3 full and sometime it will go till it is empty. If I run it in very slow I can get it to 2/3 full. But when I drive somewhere it will run out to 1/3 full. Water dumps out the over flow by it self.
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MegaDodge
Ontario, Canada
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Joined: 11/10/2003
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Here's your problem. The overflow pipe in your tank goes down two thirds of the way into the tank. It is not supposed to. So, when the overflow starts to flow, you are actually starting a siphon. Two things you can do. I'm pretty sure you can't do the first one and that is to take out the overflow pipe and shorten it to just below the top of the tank....it is always almost impossible, so here's the other fix. Get a piece of hard plastic white one quarter inch water hose, the type they use on reverse osmosis filter systems. Then drill a hole in the top of your tank, either on top, if possible or on the side, right at the top. Then insert the plastic tube into it, and secure the tube as high as possible in the compartment. That's it. How it works: When the siphon is taking down the water, as soon as the water goes below the hole you drilled the siphon will break because air will enter the tank, and the water flowing out of the tank, through the overflow will stop. I know this works, I've had to repair a tank this way. Try it.
MegaDodge
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javaseuf
Southern Cal
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Joined: 03/30/2005
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In my experience with servicing the past 30 years, the overflow fitting on a fresh water tank is just that. A fitting that is spin-welded into the tank. There is no tube inside the tank.
Also, you do not want to go drilling holes into the tank. The material is not easily sealed with any glues. This is why the fittings are spin-welded into place.
Without looking at your installation, I don't have an answer to your problem.
The previous poster's ideas sound like a possible scenario and solution but, with all due respect to the poster, I don't see them working.
Steve
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DonP
N-E-Where-USA
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Joined: 07/10/2003
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Install a reducer fitting in the overflow line just around the top of the tank. Put the larger side of the fitting on the downstream side when the overflow reaches the expansion (reducer)fitting the siphon will break. You will also need a length of larger tubing.
Don
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SCVJeff
Santa Clarita, CA.
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Joined: 07/28/2006
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Just thinking out loud here, but since it's just an overflow and you're just trying to break a siphon, is there any reason not to cut the overflow as it comes out of the tank, install a 'T' fitting and short pipe to extend above the tank?
Jeff - WA6EQU
'06 Itasca Meridian 34H, CAT C7/350
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1fastdad
mo.
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SCVJeff wrote:Just thinking out loud here, but since it's just an overflow and you're just trying to break a siphon, is there any reason not to cut the overflow as it comes out of the tank, install a 'T' fitting and short pipe to extend above the tank? DITTO
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wolfe10
Texas
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Joined: 10/08/2000
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Commerically avaliable siphon breaks are the answer.
Here are two, but they come in a variety of sizes and styles.
http://www.westmarine.com/webapp/wcs/sto........0001&Ntk=Primary+Search&ddkey=SiteSearch
http://www.westmarine.com/webapp/wcs/sto........ue&storeNum=11&subdeptNum=70&classNum=77
Brett Wolfe
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david_w28
Michigan
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Joined: 08/18/2006
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Did you just purchase it and if so was it from a dealer? If you got it from a dealer they should have some kind of a short warranty period. Because it is a 2007 and the tank drains possibly due to a manufacture defect it also might be cover if not by the motor home manufacture but the tank maker. I would check these out before I started adding or taking things apart.
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Clay L
Sioux Falls, South Dakota
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Joined: 07/01/2002
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javaseuf wrote:In my experience with servicing the past 30 years, the overflow fitting on a fresh water tank is just that. A fitting that is spin-welded into the tank. There is no tube inside the tank.
That has been my experience as well (although my experience is more limited - don't have 30 years worth). No tube inside the tank - no siphon.
However if the vent/overflow is too small (and many seem to be), pressure can build in the tank as you fill.
Many tanks are flexible enough for the top to bulge up and after it's full (actually overfull) and you stop filling, the tank will force water out of the overflow until the tank collapses back to it's normal size.
In addition most tanks are pretty shallow and when driving, water will slosh around and come out of the overflow. Mine used to drop to about half or lower. It depended on how many left curves I made.
My solution was to add a loop to the overflow tube that goes up above the top of the tank to make it more difficult for the water to slosh out.
Clay (WA5NMR), Lee,(Wife) Codi, Brandi (Shelties) and Damncat (damn cat)
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Clay L
Sioux Falls, South Dakota
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Hit quote instead of Edit
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