Fresh Water Tank Siphons

[dmac1]

I had the dealer try to rectify the siphoning problem and they moved the end of the vent hose from hanging under the trailer to up on the side. Its better but it still isn't right. You'd think that FR has produced trailers long enough to know how to make one that doesn't drain out the water as you drive down the road! I see the same issue in motorhome forums.

I called the dealer the other day and expressed my desire to have it resolved and they told me there is no fix they can do and that I should put some sort of valve on it that I open and close. Not so easy to do with a vent hose that I can't reach. Anyone know what valve they might be talking about? My best bet would be something right up at the vent, which is right next to the fill connection.

I told them that the vent hose obviously sticks too far into the tank because I can hear that it goes under water when the tank is only about 2/3-3/4 full. They said the hose can't be retracted from the tank. if I open up the underbelly do you guys think I can retract the vent hose from the tank, cut it, and reinsert? Or is it glued in or something? Surely the put the vent on top of the tank and not the side?

Thanks.

[prairiecamper]

A vent at the bottom of a potable water tank would not work, well not well anyway! And a valve on a vent line defeats the purpose, if the the end of the vent hose can be placed as high as possible above the level of water in the tank it should solve the siphoning problem!

[bubbles]

Originally Posted by dmac1

I had the dealer try to rectify the siphoning problem and they moved the end of the vent hose from hanging under the trailer to up on the side. Its better but it still isn't right. You'd think that FR has produced trailers long enough to know how to make one that doesn't drain out the water as you drive down the road! I see the same issue in motorhome forums.

I called the dealer the other day and expressed my desire to have it resolved and they told me there is no fix they can do and that I should put some sort of valve on it that I open and close. Not so easy to do with a vent hose that I can't reach. Anyone know what valve they might be talking about? My best bet would be something right up at the vent, which is right next to the fill connection.

I told them that the vent hose obviously sticks too far into the tank because I can hear that it goes under water when the tank is only about 2/3-3/4 full. They said the hose can't be retracted from the tank. if I open up the underbelly do you guys think I can retract the vent hose from the tank, cut it, and reinsert? Or is it glued in or something? Surely the put the vent on top of the tank and not the side?

Thanks.

I think they mean a simple shutoff valve at the end of the overflow tube. I had a motorhome that did this and the fix for me was to splice in a piece of tubing long enough to make a large upward loop near the holding tank and then exiting out the bottom of the coach. Had no more issues and the overflow still did its job. May not be your ticket.

[dmac1]

Originally Posted by prairiecamper

A vent at the bottom of a potable water tank would not work, well not well anyway! And a valve on a vent line defeats the purpose, if the the end of the vent hose can be placed as high as possible above the level of water in the tank it should solve the siphoning problem!

The vent was moved above the level of the tank. Still loses water. Sloshing causes some of it. Part of the issue is, I think, that they inserted the vent line into the tank too far so that it goes under water before the tank is full. Seems to start to happen about 2/3 full. Either that or the vent line isn't on top of the tank, which would an incredibly stupid design.

Anyone know how those hoses are mated to the tank? Seems like it could be extracted some so I don't pressurize the tank when I fill it.