Community Forums

jim1eddoc · 10-27-2012, 11:20 AM

Purchased a used 2011 30' Vista and discovered that I lose fresh water from tank when traveling. If the rig sits, no water loss. Over a 300 mile trip the tank will drain to 1/3. No wet areas when looking for the 2/3 water. This is a problem when dry camping :(
I assume that water is siphoning from the fresh tank into the overflow. Any suggestions to stop the action? I've tried turning on the pump and interior water in a effort to bleed off the air.
Help,Jim

kalynzoo · 10-27-2012, 11:28 AM

I have/had the same type problem. After checking everything, and the tank is clearly visable through the compartment, I too think it is siphoning during travel. I cut the siphon/dump tube just above the screen under the MH body and inserted a stop valve. I leave the valve open since I don't want to forget and overfill and perhaps damage the tank, and we seldom dry camp. However, when we took the Mexico trip, or if we plan to be less than full hookup, I can fill the tank (carefully watching) just before we reach destination and it will hold water fine.
I remember reading all sorts of fixes when I first researched the problem, such as lifting the siphon tube and re-plastic-welding, but I didn't really want to go through all that and I didn't need a perminant solution.
This works ok.

AFChap · 10-28-2012, 08:19 AM

If traveling with a full tank of water this happens on many rigs. After filling my tank, I pull the dump valve (the FRESH water dump) open for 5-10 seconds. That seems to break the siphon and I don't lose water. However, I rarely travel with more than 1/2 tank of freshwater.

zippo · 10-28-2012, 08:38 AM

Quote:

Originally Posted by kalynzoo

I have/had the same type problem. After checking everything, and the tank is clearly visable through the compartment, I too think it is siphoning during travel. I cut the siphon/dump tube just above the screen under the MH body and inserted a stop valve. I leave the valve open since I don't want to forget and overfill and perhaps damage the tank, and we seldom dry camp. However, when we took the Mexico trip, or if we plan to be less than full hookup, I can fill the tank (carefully watching) just before we reach destination and it will hold water fine.
I remember reading all sorts of fixes when I first researched the problem, such as lifting the siphon tube and re-plastic-welding, but I didn't really want to go through all that and I didn't need a perminant solution.
This works ok.

I did very much the same, only I put a 90 degree fitting on the end or the over flow line and brought it out to the edge of the Rv with a small valve in the end. For me easier than having to reach under to use the valve and I see the valve so less apt to forget and leave closed when filling the tank.

garykk · 10-28-2012, 11:37 AM

I rarely travel with a full tank of water but this past summer we were going to a state park with no hookups so filled my tank, my brother-inlaw followed us in his MH and he could see clouds of mist coming from the back of our MH a various times,usually at stop lights and steep hills..when we got to the park about 60 miles away I had lost over a 1/3 of our water.....all went out the vent tube.....

Putting a valve on it seems like a good idea..