Why Does My RV Bathroom Keep Smelling? How to Fix It? 

You’re fortunate in that your RV came with a bathroom, but the stench that keeps emanating there is making you rethink your decision. It’s hard to enjoy relaxing quality time in the RV with the smell, not to mention that sleeping is becoming more difficult too. What is causing these unwanted odors and how do you get rid of them?

If your RV bathroom keeps smelling, it’s due to these reasons:

  • Heat and humidity
  • Flushing with roof vent fan on
  • Dirty toilet
  • Toilet flange seal problems
  • Blackwater tank backups
  • Sewer pipe leaks
  • Tank vent pipe blockages
  • Unsealed bowl 
  • Dirty graywater tank 

In this article, we’ll go through each of the above causes of a stinky RV bathroom. Then we’ll present solutions for how to keep the bathroom clean, so make sure you keep reading. Your fellow RV passengers will certainly appreciate it!

9 Reasons Your RV Bathroom Has a Foul Odor

There will be no need to pinch your nose each time you enter your RV bathroom once you rule out the culprit(s). Per the intro, here are nine causes of an odorous bathroom nook to investigate. 

Heat and Humidity

Summertime is prime camping time for many RVers.

The kids are off school, you can take an extended summer vacation from work, and the weather is perfect for exploring. 

Sure, it’s hot, but it’s sunny.

Your RV has at least a blackwater tank, if not a graywater tank. 

If you need a reminder, the graywater tank stores the dingy water from your sinks, including outdoor and indoor sinks (in the kitchen and bathroom).

The blackwater tank is where all the bathroom waste goes. 

Most RV tanks are made of metal. As we’re sure you know, metal heats up exponentially on a hot day. It’s not only the metal you have to worry about though, but the contents within the tank that are essentially baking.

The heat (and especially the humidity) can contribute to bacterial growth that releases gases. It’s those gases you smell, and they have quite the gnarly odor, as we’re sure we don’t have to tell you. 

Flushing with the Roof Vent Fan On

Here’s an issue that’s oddly specific but could be exactly why your entire RV smells of sewage.

Most high-end RVs include a roof vent fan for ventilation in the bathroom. You’d use the fan after you shower to prevent the development of mold and mildew on bathroom surfaces.

Do you also happen to turn on the fan when you flush the toilet in your RV bathroom? If you answered yes, then here’s what happens.

When you flush the toilet, the blackwater tank opens, receiving the waste from the toilet. The roof vent fan will catch those toilet smells while this is happening, entrapping them, and spreading them. 

After that, it’s like the bathroom smell permeates all over the rest of the RV. Even if your RV has enclosed areas, the smell is inescapable. You’ll want to pull over at the next rest stop ASAP and get out of the vehicle.

All you have to do to amend this issue is keep the roof vent fan closed when flushing. Yes, seriously, that’s it.

Be sure to remind your fellow passengers to do the same, especially the kids. Maybe post a sign in your RV bathroom just so no one forgets! 

Dirty Toilet Bowl

The smells emanating from your RV bathroom could be attributed to specific fixtures in the bathroom, usually the toilet. 

The first thing that you want to confirm is that your toilet is clean. If it isn’t and you’re combatting terrible smells, then your next order of business is to get your RV toilet looking spic and span. 

Even closing the bathroom door cannot always keep the smells contained in just that room. Plus, even if that does work, then anytime someone goes to the bathroom, they’re going to be bombarded by sewage smells or urine stench.

That’s right, we said urine stench. If your RV toilet is a standalone toilet that’s not connected to any kind of plumbing system, then the waste has nowhere to go. 

It’s not only urine you might smell, but fecal matter as well. 

At that point, it’s more than just about how odorous your RV smells. It’s not exactly great to breathe in the scents of human waste. If you or your fellow RV passengers have breathing issues such as asthma, the condition will certainly be exacerbated. 

Toilet Flange Seal Problems

If not the cleanliness of the toilet itself, then the next area to investigate is the toilet flange seal.

Toilet flanges are made of an assortment of materials and come in a variety of sizes as well, depending on your toilet model. All flanges seamlessly link the toilet to the drainage pipe. 

The toilet flange also features a seal that keeps the flange connection airtight. That’s why you weren’t smelling anything amiss in your RV bathroom until very recently. 

Once that seal degrades or otherwise falls apart, then the smells will be nearly constant, especially if you and your passengers are always in and out of the RV bathroom. 

By replacing the disintegrated seal, your odorous issues should be no more! 

Black Water Tank Backups

You already know what your blackwater tank does, so you can imagine that if you have any sorts of issues with this tank, you and your fellow passengers will be in stink city for the foreseeable future. 

So what causes the blackwater tank to get gunked up? In most cases, it’s using toilet paper that’s not appropriate for RV toilets. 

That’s right, not every type and brand of toilet paper out there is suitable for RVs. We usually recommend buying RV-specific toilet paper just to be safe, even if a few everyday toilet paper brands won’t clog the toilet.

If you use the wrong type of toilet paper in your RV toilet, then chunks of the stuff end up in your blackwater tank. 

Unless your RV is very old, then most blackwater tanks include a series of sensors for determining when the tank is full. 

When toilet paper clumps block those sensors, the blackwater tank can no longer determine when the water and sewage levels are getting too high. 

This can lead to a backup of wastewater, which is not something you want to have to deal with!

If not that issue, then it could be that enough toilet paper sticks together and gets stuck in the blackwater tank, preventing waste from entering. The waste is backed up nearer the opening of the toilet and creates a terrible odor.

Every time you or someone else uses the bathroom, you’re just worsening that odor until the clog is so serious that sewage could begin coming out of your toilet. 

Sewer Pipe Leaks

Between the blackwater tank and the RV toilet is a sewage line or pipe. Unfortunately, through time and usage, the pipe can crack.

This isn’t always something that’s visually perceptible, which can make diagnosing the issue even more frustrating. You smell something terrible in your RV bathroom, but you just can’t figure out where it’s coming from.

Repairing a sewer pipe leak might be out of the depth of a lot of RV owners, which is fine. This is one issue that a mechanic can certainly fix. 

Tank Vent Pipe Blockages

Outside of the sewer pipe, the blackwater tank also has a vent pipe. This is connected to your RV roof from the top of the tank. 

The purpose of the vent pipe is to create a space for gases to exit as you empty your blackwater tank. 

Like most parts of the blackwater tank, the vent pipe can succumb to damage, especially blockages from too much toilet paper.

If you improperly dump the tank or the tank is overfull, and then you dump it, then the vent pipe can become backed up.

You might be able to use a garden hose to unclog the vent pipe, but if not, then it’s because too much solid waste has accumulated around it (yeah, sorry for that mental image, but it had to be said). 

Unsealed Bowl

It’s not only the RV toilet’s flange that has a seal but the base of the toilet itself. The purpose of the seal is to keep waste from spilling all over your bathroom floor each time you use the toilet. 

Once the base is loose because the seal has worn away, then of course, your bathroom is going to smell like sewage. The rest of your RV will as well. 

After resealing the base of the RV toilet, the whole vehicle should be a whole heck of a lot less stinky. 

Dirty Graywater Tank 

Since the blackwater tank is so often the culprit when it comes to RV bathroom smells, many RVers overlook the graywater tank completely. 

The graywater tank doesn’t carry human waste like the blackwater tank does, so it won’t smell as bad. That doesn’t mean the graywater tank can’t get odorous at all though.

If you haven’t dumped or cleaned the graywater tank in a bit and you’ve ruled out the other causes of RV bathroom smells, empty the tank. We bet you’ll notice an improvement in how your RV smells! 

How to Fix Unpleasant RV Bathroom Odors

In most cases, fixing the above issues will stop your odorous woes, but the following fixes for a stinky RV bathroom can also give your nostrils a much-needed break! 

Use a Holding Tank Treatment

Whether it’s the graywater or the blackwater tank, a clean tank is a happy tank, not to mention it doesn’t smell as bad.

This is where an RV holding tank treatment comes in. You pour the recommended amount of product/chemicals in and allow the stuff to work its magic.

We like Happy Campers RV holding tank treatment. A single scoop can clean a 40-gallon tank, so you get 64 treatments per bucket. For under $60 a bucket, that’s a great deal!

In very hot temperatures over 100 degrees Fahrenheit as well as in extremely chilly temps, Happy Campers says its holding tank treatment continues working. 

Compatible with septic tanks, the treatment will liquefy most toilet paper as well as waste solids.

Best of all, this holding tank treatment doesn’t smell, so you don’t have to worry about any artificial scents in your RV bathroom. 

Use a Scented Toilet Spray

Obviously, unless and until you figure out what’s wrong with your RV bathroom, the odors will persist.

That said, until you can get to the bottom of the issue, you don’t have to sit and suffer in silence. You can use a product like the Angry Orange toilet spray

This citrus-scented product comes in six-ounce bottles with a spray nozzle. You can quickly deodorize your RV bathroom so it smells fresh.

When you’re not camping, Angry Orange also says that their toilet spray is usable in the car, in household trashcans, on fabric, in shoes, and even on pet stains. 

Clean Your Toilet Bowl

Yes, this may sound like an obvious tip at this point, but we had to mention it anyway.

Don’t let your RV bathroom go too long without proper cleaning. You don’t have to scour the toilet and shower daily, but at least once a week will go a long way towards warding off unwanted smells. 

You can a toilet bowl cleaner or, if you want to use more natural products, make a solution of equal parts of vinegar and water.

Emptying Your Tanks Regularly 

To avoid putting strain on your blackwater and graywater tanks, get into the habit of dumping both tanks regularly. 

You don’t want the levels in either tank to surpass two-thirds or three-quarters. If you use your RV every day, then you should dump both tanks at least every three days but possibly up to five days, depending on how many people are in your vehicle.

Your tanks might include sensors like we talked about earlier that will indicate when it’s time to dump the tanks. 

You don’t have to pull over and do it immediately but be sure to dump your graywater or blackwater tank within that same day.

Speaking of dumping your tanks, where you choose to do so matters. RVers must always empty the blackwater and graywater tanks at designated dumping stations only.

Many park sites and campgrounds have dumping stations, as do places that allow RVers to camp such as some retail stores. 

*TIP: Once you have dumped both gray and black tanks, fill up with fresh water and dump again. Repeat as many times as necessary until the water coming out of the dumping hose is water only. I’ve had to do this 4-5 times due to toilet paper build-up in the trailer (especially if you have kids who use too much tp).

Only Use RV-Safe Toilet Paper 

Your RV toilet is not as strong as the one back home, so you have to treat it with kid gloves. That means, as we touched on earlier, only using RV-safe toilet paper.

Here are some brands and products you can purchase on Amazon to keep your toilet from clogging:

Related Reading: What types and brands of toilet paper are safe for my RV?

Use Plenty of Water When Flushing

When flushing, be sure to use enough water. You want to ensure that all the waste and toilet paper is able to completely clear the bowl and that there is plenty of liquid inside the black tank so it can easier be emptied when dumping.

Visit Our RV Maintenance Page for More Great Tips

Final Thoughts 

RV toilet smells do more than put a damper on your entire trip. It’s also not safe to breathe in that odorous air, as it could contain particles such as fecal matter. 

Getting to the bottom of why your RV bathroom smells is not always easy, but we hope the information in this guide helped you pinpoint where to start. 

Good luck! 

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

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