FTC Disclosure: I get commissions for purchases made through some of the links in this article for more information, visit our Advertising Disclosure Page.

ShareFacebook Twitter Pinterest Messenger WhatsApp Reddit Tumblr

You can subscribe to the Everything About RVing YouTube Channel for some great videos about RVing

Why Is There A Sewer Smell In Our 5th Wheel Trailer?

by Claudia
(Florida)

How to get rid of the sewer smell in your RV

My husband lives full-time in our 5th wheel because of his job, and lately, we have had sewer smells. The camper sits for a long time without moving. Are we suppose to keep the black water tank closed and dump it every so often, or can we keep it open and use the toilet and flush and the waste goes out? Please give me some advice on what to do.

Thanks

ANSWER: Hi Claudia, even when you are hooked up to a sewer system at an RV park, you should always keep the dump valves closed on both your grey water and black water holding tanks. If you do not, the sewer smell from the RV Park’s sewer system can enter your RV.

You will also accumulate many bad-smelling human deposits on the bottom of your black water tank as the liquid will go directly into the sewer system, and the solids will remain and cause a bad smell that will also enter the trailer.

Once the holding tanks get 1/2 to 3/4 full, you need to dump and flush the tanks. You then close the dump valves and pour about two or three gallons of water into both holding tanks so that the water will dilute the future waste at the bottom of the tank.

Join the Good Sam Club Today! Discounts, Tips, Tools & Much More!

Once you have added the water to the tanks you should also pour

some Holding Tank Deodorizer and Treatment in each tank. The amount of deodorizer you use depends on the size of your holding tanks. The instructions on the deodorizer will tell you how much to use.

Before leaving the campground, always dump and flush your tanks regardless of how much waste they have, and then follow the instructions outlined above.

There could be a couple of more causes to what you are smelling in the RV.

First you may have a bad Air Admittance Valve on one of your RV's sinks. To learn more about this potential problem you should read This Could Be Causing the Bad Smell In Your RV.

The other cause is actually not sewer-related. The smell could be coming from your RV's House Batteries either getting overcharged, and the electrolytes are boiling (battery acid), causing a rotten egg or sewer type smell. The first thing you should do is check the electrolyte level in the house batteries and top them off with distilled water. If they are full and appear to be boiling, you need to have the house battery charging system checked out by a Certified RV Technician.

I hope this helps.

Shop Camping World Products on Sale Now!
Do you have any suggestions or comments on this topic? You can add them to this page by clicking on the "Click Here To Post Comments" link located near the bottom of this page.

Happy RVing

RVing Al

Comments for Why Is There A Sewer Smell In Our 5th Wheel Trailer?

Average Rating

Click here to add your own comments

Rating

Battery smelled worse than sewer!!
by: Wild Bill

After a lengthy search and replacing the vent valve under the sink I stumbled on this site. Went emediately out to the battery compartment. The stench of sulfur was overwhelming and the tops of the battery had black liquid coming out of the vent holes. The battery was very hot and I'm sure on the verge of a disaster either exploding or catching on fire. New battery no odor.

Rating

Battery boiling!!!
by: Anonymous

Thank you so much for this answer. I was about to lose my $#!t trying to figure this out. Battery ended up taking over half a gallon of distilled water!!! It was literally boiling and smoking out that horrible smell. I think we may have dodged a bullet on this one. I appreciate you!

Rating

Sewer smell in RV
by: Jaycamp

We had a reoccurring smell in our 5th wheel for over a year. It would come and go. We tried everything. Finally out of desperation we removed a piece of paneling right next to the fusebox and saw there was a small leak where the toilet came through the floor. It would leak just a small amount at a time, so when we stayed in one place for awhile, the water would accumulate and smell. We discovered the floor was also soft around the toilet. We had to add a new piece of plywood and all new fittings, flanges and seals. Now everything is dry and the smell is gone. We were about ready to trade it in.

Rating

Wow!
by: Anonymous

Yas! Thank you for this post, definitely narrowed down the list of problematic things, awesomeness!

Rating

Holy Smokes it was the battery
by: Angie

Thanks a million for your post. I thought it was the blackwater connection to the house sewer. Found your info and checked the battery. This was absolutely the problem.

OMG what a relief to be rid of the stench. I have been living in this RV for 8 years and had no idea a battery could do this. Removed the battery...Now to figure out how to fix.

Rating

Battery the culprit
by: Fedor Rudnitski

Thanks so much for the info regarding a bad battery as being a possible cause. I looked everywhere for the cause of the smell and had no idea a bad battery could be the culprit. Checked it out after reading your article and sure enough that was where the odor was coming from. It was unbelievably strong and smelled just like sewer gas. Thank-you, thank-you you, thank-you.

Rating

THIS WAS THE PROBLEM
by: Wynning

Thank you for posting this information - we have been fighting a "sewer" smell for two weeks in our parked Keystone 5th Wheel. After driving ourselves crazy with gray tank, black tank, additives -- and all to no avail - we find this post!!! Opened the battery case and indeed the battery popped the cover off and is emitting a horrible sewer (sulfur) smell. THANKS AGAIN you saved us many restless nights and a lot of money trying to find the poop smell culprit!

Rating

So grateful
by: Anonymous

Hi.
We had the carbon monoxide detector go off in our 5th wheel. We turned off the propane and it was still going off so we assumed it was faulty. Then the rotten egg smell began. Thought it was the grey water as it came from the kitchen sink. We tried everything including dismantling portions of the plumbing but to no avail.

The smell continued. Then I found your site! The battery was indeed the problem!! Your comment was the only one that even suggested it.
You are a literal life saver!

Thank you again.

Rating

Battery is Culprit in Sewer Caper
by: Prairie Schooner 07

I'm so in love with this man for telling about the battery issue. Every night when I go to sleep I silently pray that I wake up without a turd tumor in my brain. I sleep with the blanket around my face and even have put potpourri pouches near my head so I can cough all night from their fumes instead of the ones creeping in from the turlet.

Then I read what he said about the batteries...I checked them and Hallelujah! They stunk like rot and I was so happy. I just can't thank you enough Mister! :) xoxoxo

Rating

Finally...An Answer to the Sewer Smell!
by: Anonymous

Thank you so much for giving an "outside the box" possible cause and solution to our problem. We had repeatedly researched the question of a sewer odor in our RV, never finding the answer until now. We were always directed to the usual causes and solutions of gray water, black water and water holding tank causes. We knew we were doing all the right things concerning these areas, and yet the smell was still there in the RV. More confusing was the fact that the bathroom area had no odor. It was the RV House Battery! Odor problem solved.

Rating

So very thankful!
by: Anonymous

This stench had gotten so bad I was thinking of moving out. Walking into a wall of smell so bad, I’m surprised the dog hasn’t keeled over. The hubby checked the batteries and the water was extremely low. Having an answer brought much joy in our little home! Thank you!

Rating

Got gas?
by: Anonymous

Stumbled across this site when searching for a fix to the sewer smell coming from the middle of my 5er. The lines were draining fine, the batteries weren’t hot, valves and Traps seemed ok.

My hubs and I were at a loss. Then I discovered my 3 year old had turned one of the stove burners on and the smell was from the unlit gas stove. So the moral of the story is, be sure to also check for propane leaks. Now to check the batteries in the carbon monoxide detectors... 🙄

Rating

Sewer odor inside RV after draining black water.
by: Marvin

Drained black water last nite and shortly afterwards smelled sewer inside. Could I have a ruptured tank?

Rating

Septic tank smells
by: Melodie

We bought a brand new 2017, 5th wheel and the sewer has smelled since the beginning. The smell fills the middle bunk house with a horrible smell every time the tank is half full. We are full timers and our son sleeps in there. We have had it serviced but they can't seem to fix it. Do I need to be concerned about his safety? . . .

Rating

Sewer gas in bathroom on trailer trailer.
by: Anonymous

Why is there a sewer smell in our travel trailer restroom even if we don't flush the toilet in awhile?

Rating

Keeping snakes out of my 5th wheel
by: Bettie

I live in a 2007 5th wheel were there have been a lots of snakes seen and a dog got bite and die i have use foam at the head of my bed to all the water lines coming in to the wires to but worry about were the refrigetator vent out side i think a snake has come in there but can't get out,i heard something drop on floor i think it was there..Plz help.live alone.nobody to help me i am disable

Rating

Sewrer smell!!
by: Anonymous

Thanks so much for the advice. We have been looking everywhere for hours for this horendous sewer smell and making me sick. I was ready to pack up and go home. My husband said, No we aren't". I called camper places and of course they were closed cause of the holiday weekend. So I decided to Google it and found this advice. And it was the battery! Thank you again!

Rating

Help
by: Marla

I have a 2000 sportsman fifth wheel and I'm having trouble with smells I thought it was my black water tank but I empty them out filling back up put rid x in it and I still have the sewer smell my gray water vent stinks like sewage and sometimes my black water doesn't I'm so confused I've never owned a travel trailer before and I live in it permanently and now I have a sewage smell every time I flush my toilet something to somebody on here said something about batteries where do I find them at

Rating

when to dump
by: 2forgetful

I was taught not to dump my tanks at the campground. My dad taught me to drive awhile, then find a station. By driving, you make sure that any solids at the bottom of your tanks get stirred up. If you haven't been parked long. Add some water to the tanks before you drive. My MH has a cleanout value, I had a horrid smell everytime I drove down the road. I was under the MH one day and found a valve. I put it in the open position. No more smell. My gray water tank was actually the source of the smell since it was not getting washed out. Good luck.

Rating

Sewer gas smell inside rv living quarters
by: Terry Mishler

Read National Fira Protrction Association 1192 for your year of RV. You're 5th wheel as per NFPA 1192 is required to have a furnace air return duct. Perhaps this could be a problem. Keystones owner's manual for our previous 2014 Mountaineer stated the owner is responsible for damages to the interior caused by carbon monoxide.

The furnace MFG. And owner's manual states carbon monoxide can kill lives. In our two 5th wheels the Mountaineer and Peterson's Excel Winslow neither had a furnace air return duct. Good luck. Best regards, Terry Mishler

Rating

Help....
by: Anonymous

Our 5th wheel toilet waste tank is clogged. We had it drained and could not find any clogs. We started using it again and we could see the tank filling up all over again. It's been full for about 6 weeks and needless to say we have not been using it. We aren't sure what to do as we tried a snake and a high power hose the first time...

Any suggestions??
Thank You!

Rating

Sewer Smell Solved
by: Anonymous

Thanks to your site the smell is gome. Hubby checked the batteries and they were bubbling! Just purchased this used 5th wheel 2 months ago. A lot to learn. We knew we had new tanks but still assumed it was a sewer smell. Then we worried it was our septic tank in our yard! Never would have thought batteries! Thanks so much!

Rating

Huge help
by: Terry

My carbon monoxide detector went off at 3 am. This is when I realized it was not my sewer and something else. I read the post about the strong smell in the battery compartment and felt the battery and it was sizzling. Once I opened the other side I could see the batter off gassing right into my trailer. Huge props to the site for helping me figure out the smell.

Rating

Air Admittance Valve (AAV) .... (edited)
by: Mike (edited)

Yep folks, Every time I flushed the toilet and washed my hands the island in the living room of my 5er collected a less than delightful smell that leaked into the room much to my wife painful chagrin!

The fix was easy. Under each sink in some RV's there is a plumbing stack with an AAV valve on top. It unscrews by hand. Replace it with any of the air admittance valves from RV supply, Home Depot, or Lowes. My under island valve was bad from the factory and constantly leaked foul air into the rig. No smell now, happy wife!

Rating

galley grey water smell
by: Anonymous

We occasionally have a terrible odor when we run water in the kitchen sink. I would smell the water as it came out of the tap, and under the sink where the flapper type vent is and no smell. Finally figured it out, the grey water roof vent is within 12 inches of the kitchen roof vent. So with the vent open and a breeze blowing just the WRONG way it comes right into the kitchen. not sure how I am going to fix it. Designed poorly it is just too close to the vent.

I am thinking of installing an extension on vent pipe to raise the funky fumes up and away from the roof vent.

Rating

Sewer gas from black water holding tank
by: Anonymous

What causes sewer gas to bubble up from toilet when flushing

Rating

Sewer smell 5th wheel
by: Anonymous

my camping neighbors were having this problem. Wasn't sewer was battery sulfur. Thank you!

Rating

Sewer smell that is not sewer
by: Anonymous

This site help me so much, after reading the comments about the batteries.. I told my husband and one of batteries was so hot and swollen it was about to explode the other was hot but not bulging. thank you for the information...

Rating

Found it!!
by: Doug

Thank you so much for the posts dealing with grey tank sewer gas. Kitchen sink plumbing is issue and the crapper is off the hook! Who would have thought dish and shower water would build such an offensive odor. I did check my batteries too but they were trouble free luckily. I can't find the one way valve that is sticking yet but the smell is overpowering there and will remove drawers tomorrow to expose more plumbing. I added a double load of black tank treatment to the grey tank to temp. alleviate problem. I love these forums.

Rating

Sewer smell
by: Dana

Oh my goodness.... I read the above post as I had tried everything to get our RV to stop smelling... guess what..... it was the batteries!! I told my husband what I had read.... we went out the RV (which we just had turned on for a trip later next week); we took off the battery compartment and wham the sewer smell hit us and the battery was hot!! Thank you for the great info!!

Rating

Leave Holding Tank Valves Closed
by: John

Many of the problems with blockages and odors when connected to a campground's sewage can be attributed to leaving the holding tank valves open. Typically, there is not enough water dispensed when you flush to move the solids through the RV hose to the septic.

Even when camping long term to full hookups, its advisable to leave your black tank valve closed and empty occasionally followed by a good amount of water.

If you have odors when moving, it may be time to replace your roof vent with a newer, more efficient one that pulls the odors out.

Rating

sewer smell in motor home
by: Deby

we have a sewer smell in our motor home as well but it comes only when we run water down the kitchen, bathroom or shower drain. It actually seems to be coming from the ceiling. What can be causing this?

Rating

sewer smell that is not sewer
by: Anonymous

When we couldn't find the sewer smell around our 5th wheel nor could the RV park manager, I turned to the internet not even knowing where to start. Well I found the only answer that we had not tried and that was to check the batteries, and sure enough it was so hot my husband could barely touch it and the smell of sewer and rotten eggs was extremely strong ... we took out both batteries and will replace them but was told the hottest one could have exploded at anytime. I am so thankful for finding this information.

Rating

ditto? ?
by: brown family

Having horrible sewage smell. We are the only 5th wheel here at trailer park. plumbing fixtures faucets replaced / swapped and hooked up for permant plumbing (ex: like home or apartment) in other words our sewage is hooked to city.

The manager has sent plumber each time he has snaked from trailer outside. Once he tried.to.snake from putside into trailer which broke gasket that houses the lines at where meets at ground. every time problem comes back and each time has backed up toilet, then shower and last time he came and snaked the pipe from roof.. still sewage smell and was told to never flush toilet paper again?? Please help.

Our lot is the.first and closest to street. Is it possiblly a problem related to city sewage? Plumber has just recently stated that he determined it was our 5th wheels sewage problem all along. So now what ? how to remedy this?

We keep paying and its never been fixed. Becoming more severe mess odor and outrageous plumbing costs for.a person on state disability income. some how have to make payments on all past plumbing visits. Please offer suggestions or.do it yourself remedies. If there is.one

Rating

Vent Stack may be plugged
by: hansfx

Hi
We noticed a smell in our trailer lately once we had used the toilet, and I noticed a slight smell in my closet - that just happened to house the two Vent poles (stacks) up to the roof. My husband actually ended up going up and taking off he protective cover, and found out that the black water stack was plugged. Once he cleared the blockage (with a very long skinny black pvc pipe) the smell disappeared! Hope this info helps!

Rating

Sewer Smell in your RV
by: Lew Mann

There can be several possible causes of sewer smell in your coach. All the above advice is valid. But, there is more.

Believe it or not, your gray tank can stink more than your black tank. The smell can enter the coach via the P-traps under your sinks and shower. Before you travel, make sure to run enough water down the drain to fill the p-traps. If left unattended the water evaporates.

If you look under your kitchen and bathroom sinks you will see the black pipes that carry the water off. At some point the pipe branches skyward and is capped by a check valve. Find the cap for your toilet too. Sometimes these valves stick open emitting sewer odor to the coach. The caps are cheap to replace. You can find them at most RV dealers or even home improvement stores.

Working at an RV dealer has its advantages. I learn about products that are not well advertised. One such product is "RV Digest-It" from Unique Manufacturing. Recently, my black tank became clogged with solids. My Service Manager added a quart of RV Digest-It to my 45 gallon black tank and filled the tank with water. We let it sit for 24 hours. During that time all the solids were digested by the enzymes and my tank was clean!

Now I use two capfulls of RV Digest-It in my black tank after I have dumped and added water. I also use it in my gray tank.

You should be able to find this or similar product at RV dealers near you.

Lew Mann
Webmaster & "Doer of Many Things"
J.D. Sanders RV Center
Alachua, Florida
www.sandersrvs.com

Rating

Sewer Smell Might Not Be Sewer
by: McElvain

Several months ago we returned from a day trip to find a strong sewer smell in and around our camper. We left the area the next day after thouroughly cleaning the tank and adding all the stuff that's supposed to help. The odor went on for a few weeks until we finally discovered it was not the sewer but the battery. It had overheated and it was sulfur we were smelling! We were told they can potentially explode when that happens. We would have sworn it was a sewer problem. So if your smell is persistent, check the batteries.

Click here to add your own comments

Return to Ask an RV Question.

LEARN HOW TO RUN 2 RV A/Cs ON A 30 AMP CONNECTION

Everything About RVing Does not sell personal information. For more information visit our Privacy Policy Page.

Amazon.com Disclosure

Everything-About-RVing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

Return to the Everything About RVing Home Page