What to Do When Your Bathroom Smells Like Sewage

Apr 25, 2022 | Maintenance & Mods

What to Do When Your Bathroom Smells Like Sewage

In this installment of our RV Mishaps series, we learn what to do when there are unpleasant odors coming from your bathroom pipes.

By Katelyn Woodmansee & Togo RV

Photo: Ashley Rossi

Welcome to RV Mishaps, a content series written by RVers about problems they’ve encountered on the road, how they solved them, and lessons learned. Have a mishap story of your own that you’d like to tell? Send us an email at pitches@roadpass.com

I bought my first camper when I was 21 with no experience. It took me a while to figure out the perfect routine with my travel trailer. Then, when I met my husband, we traded in my rig for a Class A motorhome. It’s an older model that came with some problems, but we were excited to get out on the road. 

A view of an RV toilet and a roll of toilet paper
Photo: Ashley Rossi

What Went Wrong

As soon as we started using the bathroom, a rotten smell came up through the pipes. At first, we tried holding tank deodorizers like AquaMax, Porta-Pak, and Aqua-Kem. Unfortunately, those products only masked the smell for a moment, but it quickly returned. We tried pouring bleach down the drains, and cleaning and dumping our tanks daily, but the smell seemed to only get worse. After trying every cleaning product we could find and emptying out our tanks over and over, we stopped using the bathroom, which completely defeated the purpose of our rig upgrade. It wasn’t a sustainable solution and there was still an odor. 

With white flags raised, we sought out solutions from every medium, but nothing gave us lasting or sustainable results.

Lessons Learned

After much research, we discovered a component on our Dometic 300 Series toilet that needs to be changed every few years depending on usage: the toilet flush ball seal. It’s a part that I had no idea existed but is detrimental when it comes to controlling the natural odors of an RV toilet—as well as helping keep the bowl clean. If the toilet bowl doesn’t hold water, it’s a good indication that it needs a new seal. 

Close-up of a ball seal inside an RV toilet.
Ball seal inside an RV toilet. | Photo: Ashley Rossi

RVs use different toilets and bowl seals. Make sure you order the proper seal for your toilet model.

The good news is it’s an easy change, just a little gross—so make sure you buy gloves beforehand. You can purchase a two-pack of these seals on Amazon, that way you have one ready for the next time you need to replace it. 

Make sure you follow the instructions and install the ball seal with the proper side facing up. Some types of seals will require the removal and disassembly of the toilet.

For an easy install, use a form of biodegradable lubrication on the ball seal—I used vegetable oil. When you open the toilet bowl, stick your hand in and easily work the old seal out. This is the small black seal that’s directly on the outer ring of the opening of the toilet. Once the old one is removed, clean it to remove anything that’s stuck between the seal. Then, set the new seal in place, which may take some maneuvering. To check if it’s installed correctly, close the toilet bowl and fill it up with water—if your toilet holds water, you did it right.

Dropping the ball seal into the tank is easier than you’d expect. If you do drop it, the hardest and grossest part will be trying to get it out of your tank safely.

Once your new seal is installed, clean your tanks. Start by emptying your black water tank completely followed by your gray water. Next, completely flush both tanks with fresh water to push out anything left behind by the initial emptying of the tanks. Newer RVs often have this feature and will save you time. For our RV, we filled up buckets of water and dumped them into our toilet. 

RV-friendly toilet paper from CAMCO
RV-friendly toilet paper from CAMCO.

Now that your tanks are cleaned and empty, everything else is merely preventative. We avoid throwing toilet paper into the toilet directly because it takes more time to dissolve. If you choose to dispose of toilet paper in your system, be sure it’s septic-friendly. General RV toilet maintenance is pretty simple—like routine cleaning, using RV septic cleaning and deodorizing products, and regularly emptying out your tanks.

Another preventative maintenance tip for unwanted bathroom odors is to fill your toilet with bleach water weekly and let it soak until the next use. 

Related Everything You Need to Know About RV Toilets and Black Tanks

A sewer vent pipe leak or bad toilet floor flange seal can also create sewer odor inside the RV. Always change the floor flange seal anytime you remove the toilet.

Although RV sewage sounds like a dirty job, it can be a breeze to deal with as long as you’re mindful of the materials you use and maintain a premium cleaning routine.

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Katelyn Woodmansee

A girl, boy, and two dogs traveling the U.S. and writing music.

Togo RV

Pronounced [toh-goh], and rhymes with logo, Togo RV makes RVing easy so you can spend more time doing what you love. Want more miles, less trials? Run with Togo.