Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 07-25-2011, 01:15 PM   #1
Junior Member
Jamba's Avatar
Join Date: Jun 2009
Posts: 5
Fresh water tank overflow

When I fill the fresh water tank on my Winnebago Vista 26P and it reaches full, it starts overflowing out the overflow tube and by gravity/suction, takes 12-15 gallons before it finishes overflowing. Even if I stop filling before full, when I start driving, the gravity/suction
effect takes 12-15 gallons off the top of the tank. Is it possible to plug the overflow tube or
is it needed for a venting effect on the system?

Jamba is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-25-2011, 02:05 PM   #2
Senior Member
johnsonjm209's Avatar
Monaco Owners Club
Ford Super Duty Owner
Join Date: Oct 2010
Posts: 295

My overflow is underneath the RV (03 H.R. Vacationer). Many times if I am going to be on the road for a few days without the benefit of an RV park, I will take the "rubber" nipple off of the bottom of the overflow pipe. There are threads there. I replace it with a galvanized cap and fill it up until I can tell the tanks are full at the "outside fillup location". But, I am very careful to monitor it so I won't have an overflow problem somewhere else. When I get to a site with amenities, I replace the rubber nipple.

Joe from Ct.
johnsonjm209 is offline   Reply With Quote
Old 07-25-2011, 04:12 PM   #3
Moderator Emeritus
Gary RVRoamer's Avatar

Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,632
Your tank needs a vent or the pump won't be able to suck water after a short while. Some tanks have a separate vent, but some rely on the overflow tube. All you can do it try.
Where does your overflow exit the coach? Is it possible to raise the end above the top of the tank to avoid the siphon action? One coach we had drained behind the rear cap, so the exit form the hose was way up high.
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 07-25-2011, 04:19 PM   #4
Senior Member
Senior Chief's Avatar

Vintage RV Owners Club
Fleetwood Owners Club
Join Date: Jun 2009
Location: Somewhere in the woods in Belfair, WA, WA
Posts: 1,250
If you can physically get to the overflow tube, you can put a T in it at its highest point, and add an open vent tube (smaller diameter) going straight up a foot or so. This will kill the siphoning action and won't interfere with the overflow tubes's ability to handle the overflow water
Life rocks when your house rolls
Senior Chief
& the Cheese Queen

Senior Chief is offline   Reply With Quote
Old 07-25-2011, 04:23 PM   #5
Senior Member
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
YES, the siphon needs to be interupted. However, if you fill it up and some drain out, just add about 80% of that amount and you are good to go.
targaboat is offline   Reply With Quote
Old 07-25-2011, 09:29 PM   #6
Senior Member
scenic route's Avatar
Join Date: Jan 2010
Posts: 1,767
Ours does the same thing. Also, if I filled until the 'full' light was on steady, water would siphon out if I parked on an angle with the tank on the low side. I started filling the tank just until the 'full' light started to flicker and stopped the fill...that seems to have helped on both counts. Bob
Jan and Bob

RIP 'Squeaky'
scenic route is offline   Reply With Quote
Old 07-26-2011, 09:50 AM   #7
Senior Member
JCM's Avatar
Workhorse Chassis Owner
Triple E Owners Club
Join Date: Nov 2004
Location: Williams Lake,BC Canada
Posts: 1,023
Here is what I did. I have an extra day of water now when traveling - dry camping. BUT mske sure that they are open when filling or that you have a vent in the filler.
Attached Thumbnails
Click image for larger version

Name:	P1040038.jpg
Views:	93
Size:	247.6 KB
ID:	12438  

2007 Triple E - Empress Elite - Freightliner
WH 22 owner for 7 years
JCM is offline   Reply With Quote

tank, water

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Filling the fresh water tank after winterizing kartvines Fleetwood Products Owner's Forum 5 05-12-2011 08:42 PM
How to sanatize fresh tank if you don't have a gravity water fill (2010+ Models) gdbontly Excel Owner's Forum 11 09-14-2010 02:12 PM
Fresh Water Tank Overflow wlf00 Winnebago Industries Owner's Forum 1 06-30-2009 08:10 PM
TROUBLE W/USING FRESH WATER TANK OpaRon Newmar Owner's Forum 4 11-24-2008 04:20 PM
Fresh water tank overflow pipe yudamann Tiffin Motorhomes Owners Forum 3 06-20-2008 02:44 AM

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:43 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.