Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > iRV2.com General Discussion
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 09-17-2016, 06:24 PM   #1
Junior Member
Join Date: Sep 2016
Posts: 10
2" Grey Tank Plumbing...Problem?

Bought a travel trailer a couple weeks ago, so I'm on a learning curve. Should I be concerned that the gray tank drain begins with a 3" pipe, then immediately becomes a 2" pipe with a 90-degree fitting, and exits the trailer with a fitting that changes the plumbing back to 3" with a standard sewer connection? The manner in which the 2"-3" is plumbed traps a little water in the drain pipe. This water will freeze in the Winter months. I'll try to attach photos to this post.

Is this a standard in the industry...3" to 2"? Why not use a 3" pipe all the way? Wouldn't that flush better? Should I insist that the dealer change out the 2" pipe for a 3" pipe?

Opinions welcome.

Attached Thumbnails
Click image for larger version

Name:	3-2.jpg
Views:	61
Size:	219.6 KB
ID:	139221   Click image for larger version

Name:	2-3.jpg
Views:	65
Size:	275.4 KB
ID:	139222  


BKWDS 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 09-17-2016, 06:37 PM   #2
Senior Member
Join Date: Sep 2012
Posts: 4,034
Typical, probably not a problem. Assuming you drain the tank as part of winterizing there might be a little water there but it is free to expand upward. Most likely you will dilute it or replace it with antifreeze when you fill the traps.

nothermark is offline   Reply With Quote
Old 09-17-2016, 06:47 PM   #3
Senior Member
Mr_D's Avatar
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 22,393
Not a problem IMHO. Our last three MH's have been this way and never had a problem.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '05 Odyssey
Mr_D is online now   Reply With Quote
Old 09-18-2016, 07:21 AM   #4
Moderator Emeritus
Gary RVRoamer's Avatar

Fleetwood Owners Club
Freightliner Owners Club
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 16,436
Since the plumbing standard for gray waste lines is only 1.5", I see no problem. However, it seems odd they necked it down to a smaller size for that short distance, when they know a 3" outlet is required for a standard sewer hose connection. Of course, it is equally odd that they put a 3" outlet in the gray tank. At a guess, I suggest that they are using a tank that is also used for black waste in some other model and they decided to build all the tanks with the same size drain port and adapt to whatever model they get installed in. That's the sort of tradeoff that production engineering makes to reduce the number of parts they have to deal with.
Gary Brinck
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL
Gary RVRoamer is offline   Reply With Quote
Old 09-18-2016, 07:27 AM   #5
Junior Member
Join Date: Sep 2016
Posts: 10
Great, I'll not bother the dealer with a non-issue. Thanks
BKWDS is offline   Reply With Quote
Old 09-18-2016, 09:10 AM   #6
Senior Member
monkey's Avatar
Join Date: Sep 2011
Location: Arkansas
Posts: 1,760
Massive looking tires on that trailer !!!!
Monkey, pilot of a Great Dane hauler,
2015 Silverado 2500 Duramax/Alison 4x4 CrewCab 2016 Cougar 28SGS
monkey is offline   Reply With Quote
Old 09-19-2016, 08:31 AM   #7
Senior Member/RVM #90
MSHappyCampers's Avatar

Monaco Owners Club
Join Date: Nov 2002
Location: Columbus, MS
Posts: 19,297
No problem! I think our MH has 2" pipe on the gray tank!

Joe & Annette

2002 Monaco Windsor 40PBT, 2013 Honda CRV AWD
MSHappyCampers is online now   Reply With Quote

grey tank, plumbing, tank

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
"New Posts," "Today's Posts" and "List Subscriptions" Not Current l1v3fr33ord1 Forum 101 | Announcements | Member Concerns 3 02-23-2016 06:28 AM
Problem With DS 4369 "Hood" "Prop-Bar" hugh37 Newmar Owner's Forum 7 08-24-2015 08:24 AM
"Check Engine Soon"/overdrive "Off" problem drsail Ford Motorhome Chassis Forum 5 08-08-2014 03:09 PM
How to "Fix" Grey Tank Leaking Valve??? winnie32v Class A Motorhome Discussions 2 07-13-2012 01:23 PM
BLACK TANK: "can we" or "can we not" leave the black tank open in an RV park?? doodlebug52 Travel Trailer Discussion 15 12-02-2009 09:56 PM

» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:16 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.