Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Country Coach Owners Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Thread Tools Search this Thread Display Modes
Old 12-20-2010, 02:22 PM   #1
Junior Member
Country Coach Owners Club
Join Date: May 2010
Posts: 9
Weird black tank odor problem

We have a 2006 CC Inspire 360 that has a serious odor problem only under certain conditions. Flushing the toilet (electronic type) by itself is not a problem and there is relatively no odor, but have either of our 2 roof vent fans on, and LOOKOUT! It is awful. It seems that the negative pressure in the coach pulls the black tank odor directly up into the bathroom and beyond. We had a 5th wheel before and with the exhaust fan blowing out, never had that problem.

Does anyone know of a way to prevent this from happening? A lot of times it is nice to have the vent fan(s) on (which by the way, only exhaust out), but if they are on you cannot flush the toilet without the odor.

Someone suggested that the black tank vent may be blocked, but in my mind, that does not make sense since an open vent would assist in air being drawn through the tank. I am stumped.

arrowheadbob 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 12-20-2010, 03:04 PM   #2
Community Administrator
JohnRR's Avatar

Fleetwood Owners Club
Workhorse Chassis Owner
Join Date: Sep 2010
Location: Marquette, Michigan "Da UP"
Posts: 17,185
Being new to RV's the two times it's happened to me I added more deodorant mix and it cured the problem actually the first time I had cheap stuff the RV dealer gave me when I bought the thing and the second time I just did not put in enough as it got towards the full mark with the better stuff I got from the 2nd RV dealer who cured my first time problem. Once I put more of the better stuff in the problem was cured until I was able to dump.

John & Cathy R.
06 Pace Arrow 38L W24
08 14 Lincoln MKX AWD
See My RV Upgrades
JohnRR is offline   Reply With Quote
Old 12-20-2010, 03:13 PM   #3
Senior Member
Wanabee FTer's Avatar
Gulf Streamers Club
Ford Super Duty Owner
Join Date: Jul 2010
Location: Golden Village Palms, CA
Posts: 1,988
Blog Entries: 12
Hi arrowheadbob,

I have had this concern on my coach (different make and model)
I found the problem was caused by a poor seal on the ball valve (Sealand toilet) Mine had a slow leak that was evident when the bowl was full of water. It would take a while, but the water leaked out of the bowl and into the black tank. With the bowl empty when the fan was turned on, it would draw odor out of the black tank through the leaking seal. I was able to temporarily repair mine with CLR calcium remover.

Wanabee FTer is offline   Reply With Quote
Old 12-20-2010, 03:43 PM   #4
Senior Member
AFChap's Avatar
Winnebago Owners Club
Spartan Chassis
Join Date: Aug 2002
Location: ...hopefully on the road!
Posts: 4,776
It seems pretty obvious to me that if you are pushing air OUT, the negative pressure WILL pull air IN wherever it can ...and an open commode flush valve is as good as an open window in that regard. And if the tank vent were blocked, it would be LESS likely to allow air to be drawn up through the commode. You can try to cover the sewer gas with chemical smells, scents, aromas, etc, but if that is the only other opening when you are running 1 or more exhaust vents, the vent(s) WILL pull air in through that opening.

We never run our vent fans w/o having a source of air for them to pull from. I can hear a big difference in the drag on the fan motors when they are trying to push air out w/o having air coming in somewhere. If we have multiple vents open, at least one of them will be turned off so air can come in there while air is going out the others. (None of our Fantastic Fans are reversible models, but I altered them a few months ago so they are now all three reversible.)
Paul (KE5LXU) ...was fulltimin', now parttimin'
'03 Winnebago UA 40e / '05 Honda Odyssey toad
AFChap is offline   Reply With Quote
Old 12-20-2010, 03:50 PM   #5
Community Administrator
NLOVNIT's Avatar

Pond Piggies Club
Fleetwood Owners Club
Ford Super Duty Owner
LA Gulf Coast Campers
Outdoors RV Owners Club
Join Date: Mar 2002
Posts: 23,783
Blog Entries: 1
I found the only way to keep the smell from wafting out of the tank while flushing is to NOT have the overhead vent fan on. For just the few seconds it takes to flush, it's worth it not to smell the "tank perfume" by turning off the vent fan. Luckily, our bath fan switch is just an arm's length away from the throne - easy to reach.

Commenting on the negative air pressure statement you made, our coach addresses that with this sticker. It's located on the Splendide, but I'd think it would pertain to anything that would exhaust inside air. We always have a window cracked open if any exaust fan (bath, salon, stove or dryer) is running.

Attached Thumbnails
Click image for larger version

Name:	P1010036.jpg
Views:	76
Size:	197.8 KB
ID:	7320  
Lori & Dave - FMA #3415 | FMCA #F419886 | RV/MH Hall of Fame Lifetime Member
2006 Fleetwood Bounder 36Z & 2014 Honda CRV EX-L AWD, My iRV2 Photo Albums
How is it one careless match can start a forest fire but it takes a whole box to start a campfire?
NLOVNIT is offline   Reply With Quote
Old 12-20-2010, 07:26 PM   #6
Senior Member
Join Date: Feb 2010
Posts: 4,510
Talking Weather seals are working...

Sounds like everything that seals the inside from the outside is in wonderfull condition.

Flush the toilet to get it full of water and test the fan, if no bubbles or odor then let it get dry, flush with water off or switch off power mid flush.

Retest fan, of odor then souce is confirmed.

Next, find a window to leave open.
TQ60 is offline   Reply With Quote
Old 12-20-2010, 07:44 PM   #7
Senior Member
palehorse89's Avatar

Newmar Owners Club
Join Date: Oct 2009
Posts: 8,105
I had the same problem in the bathroom when traveling and found it to be the rubber flap on the plumbing under the sink was stuck down and wasnt working. I unscrewed this off of the sink plumbing and worked the rubber flap loose and screwed it back on and the sewage oder problem we had from time to time for months was gone and has not returned.
2000 Newmar MADP 4060, 350ISC, Spartan MM, IFS 2011 Jeep JK, M&G Braking, 2014 MTI 27' Hog Hauler, Wireless brake control, 2006Ultra & 1989 Springer
palehorse89 is offline   Reply With Quote
Old 12-21-2010, 07:33 AM   #8
Registered User
Join Date: Sep 2010
Posts: 2
What you are experiencing is normal. The toilet is a direct drop to the holding tank and when you have Fantastic fans running, it will pull the odor from the tank. Having a window cracked may lesson the odor, or just turn off the fans.

01 Magna 5999
truk4u is offline   Reply With Quote
Old 12-26-2010, 08:45 PM   #9
Junior Member
Country Coach Owners Club
Join Date: May 2010
Posts: 9
Thank you all very much for the replies, especially during the Holiday season.
Sounds like I will need to keep a window open or turn off the bathroom fan when occupied. I guess we never had this issue in the fifth wheel because it was probably not so tightly sealed as the motorhome.

arrowheadbob is offline   Reply With Quote

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
Grey water tank flows into Black water tank? dgmelp Class A Motorhome Discussions 12 03-30-2011 09:06 PM
Leak while flushing out black water tank Samflhomes RV Systems & Appliances 10 07-02-2010 06:44 PM
Black Tank Sensor shows Empty - even when full! DavidLyle Winnebago Industries Owner's Forum 8 02-17-2010 02:38 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
Black Tank Repair Lindaxtwo Excel Owner's Forum 31 08-20-2009 06:24 AM

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:29 PM.

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