Skip to main content
Topic: Sewage smell (Read 1273 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Sewage smell

Yahoo Message Number: 112010

2003 Country Coach Cascade Allure - I have a sewage smell in the coach after a few days of camping. Its happened two different times recently. I've been following a routine of dumping the black and grey water then disconnecting the hose and placing it in a seal storage container. No initial smells but when I crank up and take off its terrible! I also have a small amount of water in the toilet when leaving out. You can also get a whiff of it through the kitchen drain.

Also the black tank seems to empty completely but the meter still shows 1/2 full afterwards.

Anybody have a solution?


Re: Sewage smell

Reply #1
Yahoo Message Number: 112012

What I've noticed with my coach is what I think is the water being sloshed out of the drain traps to some degree while moving. If I combine that with suction - an open kitchen window, then I seem to get gray water smell. Or now that I have a washing machine on board, if I don't use that for 3-4 weeks, the water has evaporated from that trap.

Of course this means I'm smelling gray water and not black- but wow can gray water be stinky!

I've had good luck with no open coach windows, and making sure I do a load of laundry every week or two in the coach. And/Or set the vent or A/C to draw in outside air adding some positive pressure to the inside.

On my black tank meter, I do often get false non-empty readings. Often they go away after a day or two. I do have tank flush nozzles installed which sometimes help. If I really get a stuck high reading, I fill up the black water tank 1/2 way, then go for a drive and make sure I swerve back and forth at low speed, sloshing the tank well, then when draining, it almost always has cleared up. Basically either toilet paper or other debris gets on top of the sensors or creates enough of a bridge to the ground to show a reading. When I first bought my rig, it had not been used consistently for some time, and so it was really stuck showing 1/2 tank, but after constant use for a few months, it at least can be cleared reliably.

A trick I also use on the rare occasion that a dump station has no fresh water hose to use my installed purge nozzles... I of course drain the black first, then close that valve. I do a short open on the gray to clear the hose. Then I remove the hose and put the travel cap back on. Then I open up the gray again, wait till all the air bubble sounds stop, and open the black. The gray water fills up the black tank probably half way (if your gray is full). Then close the gray & black. I use the small cap on the travel cap to drain the Y into the loose hose end, then rehook the hose and drain the black again. Using my clear connector off the Y, I can see this really helps clean the black tank out beyond the one drain with no fresh purge. Before I figured out this process, I would dump a few 5 gallon pails into the toilet after the first drain, then drain again.


2000 CC Allure #30443
Currently in Colorado

Re: Sewage smell

Reply #2
Yahoo Message Number: 112013

A couple of times I've had bad timing closing the black tank valve. I usually open the gray while the black is still draining, but almost empty. I usually operate the black valve a time or two while the gray is draining strong to clean the black valve. A couple times the gray finished draining while the black valve was still open. This resulted in a terrible smell in the coach. I now pay more attention and make sure the black valve in closed completely before the gray tank is empty.


2004 Intrigue 11836

Re: Sewage smell

Reply #3
Yahoo Message Number: 112016

Also check our rigs air valves... And if you are in real hot weather, with the sanitation side basement door facing the hot sun - well, it does add to the 'cooking' process:)!

Air Valves do fail. Usually one out by the kitchen sink, another by the bathroom sink that also covers the shower, and then if you have a washing machine it has one too. I do not believe the Black tank has one(?).

Don't cut corners when replacing them, I believe from other posts over the years, that Studor and Oatey are worth the price of purchase:)!

Are you using Happy Camper? (Or similar, though for us, Happy Camper has seemed to work the best for us:)!.

And yes to regular flushing of the tanks. I you don't have take flush valves, have them installed, and use them...

This time of year, you see these kinds of posts more often - as HEAT will cause bacteria to do it's thing:)!

May the odor, be away from you,


04 Allure 31017 (And also a High Cascade:)!)

Re: Sewage smell

Reply #4
Yahoo Message Number: 112026

I had a similar problem a month or so ago. We were bobbing around on I-5 near Mt. Shasta when the DW started complaining of the smell. I had her run some water in the sinks and that fixed our problem....all the bobbing about made us lose our liquid barrier in the sink P-traps.

03 Allure Cascade 30832

Re: Sewage smell

Reply #5
Yahoo Message Number: 112032

The smell is most likely from the grey tank via one of your sink air admittance valves. When the smell occurs, stick your nose under each sink and you'll probably find the culprit. Another possibility is the washer dryer standpipe trap may be dry. Pour some water down that and see if the smell is alleviated.

Good luck

George in Birmingham(currently in Santa Fe for the summer) '03 Magna 6298

Re: Sewage smell

Reply #6
Yahoo Message Number: 112033

Add the shower to the list of traps to make sure have water in them. This is our biggest contributor since we seldom use it.


They say wine improves with age! As I enter my golden years, I say age improves with wine! The Born Loser

Re: Sewage smell

Reply #7
Yahoo Message Number: 112037

Had the same problem. We don't use our washer/dryer and the drain had dried up letting the grey water smell permeate the coach. Ran the rinse cycle and all was well again.

Casey Jones

2003 Islander (CC chassis)

sewage odors

Reply #8
Yahoo Message Number: 112050

Has there been recent traffic wrt toilet odors and how to control them, we recently changed chemicals and now have a sulphur smell.
Gerry and Penny Bayles
2006 Inspire 360

Re: sewage odors

Reply #10
Yahoo Message Number: 112053

We have a 2008Intrigue. If you want no odors, on your travel days, mix a cup of dishwashing liquid, not dish soap, with a half cup pine sol to your black and gray tank. Dishwashing liquid is what removes grease and grime from your dishes without damaging your dish washer. Fill tanks half way when you can dump at the end of the day from sloshing around, you will have spotlessly clean tanks. You will never need to add anything else to your tanks.

Re: sewage odors

Reply #12
Yahoo Message Number: 112055

That's what I do also. The dishwasher soap won't Suds up and give you a problem that way. I also have a procedure when I put my coach to bed for a while I rinse the tank real well, fill it up half full of fresh water and put a gallon of vinegar in each tank black and grey water. Rinse out before you take off again. I never ever have an odor problem. By the way on the electrical thing Echo Chargers are designed to only charge the other Banks when the initial banks are full and they will only charge similar to a maintainer charger. On my coach I put a 250 amp master switch and combine both engine batteries and house batteries all the time. If I go dry camping I worry about having engine battery I go back and turn the switch off to separate the banks. I also carry the big heavy duty capacitor charger so in case I do run into trouble I can at least start my generator to charge the system. Been operating this way for 10 years with no problem .

Sent from Yahoo Mail on Android

Re: sewage odors

Reply #13
Yahoo Message Number: 112056

Yes to Happy Camper regular user.

Yes to several oz's of Dawn in the Grey and Black and half a tank of water between campground runs, if needed. (Maybe once every 18 months or so, we'll do this.)

When we first bought our coach, it was not as well cared for as it should have been. (Low usage, and miles. Chassis and generator were yearly maintained, as well as a wash and a wax, by the dealer that first sold the RV. But many items like tank management, was not done by the owner in this time. And heck, some systems had never been used either:)!).

So for heavy and or baseline maintenance catch up of Black and Grey tanks, here are some other tips & tricks, shared by many over the years: > Same half full Black and Grey, and then also stop and get 20 lbs of cubes to put down the toilet. Then drive. The ice cubes help clean the sides, and probes.
 P-Trap maintenance. Box of baking soda, gallon of white vinegar. Put power down the sink drain, and pour white vinegar until it stops foaming out.
 Black tank Backing Soda and White Vinegar. Full box of soda power, and two, or three gallons of vinegar, then drive around a bit.
(Caution on both of the above usage of baking power and white vinegar. They will gas up a bit, so stay well back and if in doubt, safety goggles and even gloves are not a bad idea.) > About every 4-5 years, buy a new coach!!! (A bit drastic, but I find it's a good way to get around the DW. Now Dear, we have to get a newer coach, as our crapper tank is dirty:)! (Just a tad bit of what my DW calls 'Non Smitty Humor' in the last tip!).

Best to all,


Re: sewage odors

Reply #14
Yahoo Message Number: 112057

We also used Happy Camper for a number of years (worked great) however, we just switched to a product called Unique, its liquid. It seems to work well, no complaints. We started using a concoction when we are going to be driving that consists of Dawn Liquid, Calgon Liquid (2/1) ratio and enzyme of choice. Works well, the green light on the flush pad turns green.

Buying a new coach is out, want to live long enough to do everything we want to do in this one. My Dad use to convince my Mom that there was something wrong with the car and they needed a new on, it always worked.