Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > GENERAL DISCUSSIONS > General Discussions about our Montanas
Click Here to Login

Thread Tools Display Modes
Old 08-09-2018, 05:51 PM   #1
Seasoned Camper
Mosnowman's Avatar
Join Date: Apr 2017
Location: Little Slice of Heaven..Missouri
Posts: 82
M.O.C. #19731
Gray Tank Odor / Black Tank Odor

I have a 2018 3721RL and have some new odor problems popping up. No problems when new, started roughly 6 months in.

Gray Tank: I keep tank closed and only open when dumping. Here is what started happening after DW completely filled (over filled ) the gray tank. It now occurs even after dumping. Pungent Gray Tank Odor is coming from shower drain. I put a red solo cup over drain, and that works as a temporary solution. Stops odor.

Black Tank: Only open when dumping. When flushing toilet there is an intense black tank odor that fills bathroom. Happens without fan running. It didnít use to smell when flushing.

2018 Montana 3721RL
2018 Ford F350 6.7 Turbo Diesel
Life Comes Down to a Simple Choice..Get Busy Living or Get Busy Dying
Mosnowman is offline   Reply With Quote
Old 08-09-2018, 05:59 PM   #2
Montana Master
Join Date: Feb 2006
Location: Denver
Posts: 905
M.O.C. #5329
Blocked vent tube?
scattershot is offline   Reply With Quote
Old 08-09-2018, 06:03 PM   #3
Montana Fan
DadsHemi's Avatar
Join Date: Sep 2017
Location: Florence
Posts: 319
M.O.C. #20472
Sounds like a blocked vent or vents, also sounds like the flap in the shower drain is not working properly.

2018 Ram 3500 Megacab 6.7 Aisin
4x4 4:10 Gears Lariame
2017 Montana 3160RL
DadsHemi is offline   Reply With Quote
Old 08-09-2018, 06:16 PM   #4
Site Team
Join Date: Aug 2007
Location: Omaha
Posts: 6,028
M.O.C. #7560
Steve-- First of all are you using anything in the tanks for breakdown of solids, especially the black tank but it can be used in the gray tanks also. Second, when you dump the black tank are you back flushing it also with the backflush for the back tank? It does sound like the vent pipes may be blocked but it could be just that bacteria has built up in both the tanks to cause this problem. The shower gray should have a backflow valve in the drain pipe that my need replacing or the gasket in it may be bad or reversed it's position. This could cause the problem also for that tank but the bacteria build up sounds like the culprit to me in both tanks. I use Happy Camper in all my tanks and haven't had a problem with smell or solids at all on either one of my rigs.
Rondo is online now   Reply With Quote
Old 08-09-2018, 06:19 PM   #5
Montana Fan
DadsHemi's Avatar
Join Date: Sep 2017
Location: Florence
Posts: 319
M.O.C. #20472
We use the Happy Camper Cem as well, best I’ve ever used.

2018 Ram 3500 Megacab 6.7 Aisin
4x4 4:10 Gears Lariame
2017 Montana 3160RL
DadsHemi is offline   Reply With Quote
Old 08-09-2018, 07:18 PM   #6
Kyle and Lisa
Montana Fan
Join Date: May 2018
Location: livingston,tx
Posts: 417
M.O.C. #21685
We started using the TST treatment from Walmart after noticing an odor when running the ceiling vents, we use it every time we move and have not noticed an odor since, and we use it in the grey tanks as well. Recently after draining the main grey tank it went from 2\3 to empty after seeing at 2\3 for 11 months when we know it is empty !
Kyle and Lisa is offline   Reply With Quote
Old 08-09-2018, 09:46 PM   #7
Montana Master
DQDick's Avatar
Join Date: Jun 2011
Location: Wilsey
Posts: 16,709
M.O.C. #11455
Happy Camper for us also. The shower drain problem sounds like what Rondo indicated. In the drain line below your shower is a HEPVO valve. That uses a membrane to stop oders just like a P trap uses water. If overflowing the tank reversed the membrane that could be your problem.
Dick, Joyce, Diego, Picatso and Gustav
2017 3720 RL, MorRyde pin box
2017 3500 Dodge Maxi DRW 4X4, Pullrite Hitch, IS, Disk Brakes, 3rd AC, Winegard Traveler, Bathroom door mod, Dometic 320, couch for desk swap, etc.
DQDick is offline   Reply With Quote
Old 08-09-2018, 10:36 PM   #8
Montana Master
BuilderBob's Avatar
Join Date: Sep 2017
Location: Tacoma
Posts: 1,518
M.O.C. #20475
Sound like you have a problem with the HEPVO valve in the shower drain it replaces the pee-trap that most drains have there is a one way rubber valve that can get worn or damaged and not stop the tank oders from coming in. If you are getting oders from the black first of all does the toilet hold water in the bowl if not that would be the first thing you need to fix the water keeps the oders out. The next is what kind of tank Cem! are you using Happy Camper is the best out there you can buy it on Amazon.
Bob & Carol Washington St
2017 HC HM352RL 2018 Dodge 3500 laramie CC LB 4x4
Curt Q25 with puck system, Factory air bags
Happy Trails
BuilderBob is offline   Reply With Quote
Old 08-11-2018, 01:06 AM   #9
Montana Master
Join Date: May 2017
Location: new caney
Posts: 791
M.O.C. #19873
I use happy camper also with no odor. I don't need some brand that is lemon fresh or what ever the flavor is of the day. The best smell is no smell period. Rondo may be correct in that bacteria may have built up in tank. Happy camper makes a product as well as others that you can pour down the toilet and fill about half full on your next travel day and let it slosh around while traveling. Sometimes the tanks just need a good cleaning. If this doesn't work then i would look at other options that have been stated on this forum. Good luck.
Texan is offline   Reply With Quote

Thread Tools
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
Forum Jump

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 12:36 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.