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5 Reasons Why Your RV Toilet Stinks

5 Reasons Why Your RV Toilet Stinks

A stinky RV can ruin your adventures in a hurry. No matter where the odors are coming from, you’ll want to resolve it quickly. There’s not much worse than odors coming from your toilet. It surprises us how often people ask, “Why does my RV toilet stink?” in online groups. If you’re one of them, we want to help.

Today, we’re looking at why your RV toilet stinks and what you can do about it. We’ll share a few things you can do to have an odor-free RV before your next trip. Let’s get started!

Close up of a toilet in an RV
Keep your RV sweet smelling by monitoring your RV toilet to prevent any unpleasant smells.

How Does an RV Toilet Work?

The most common RV toilet type relies on gravity to function. A storage tank lies directly beneath the toilet, which RVers call a black tank. The black tank holds the waste until the RVer can find an appropriate spot to dump it.

When you need to flush, you’ll use a foot pedal or handle to open a trap-door-like seal in the bottom of the toilet bowl. Once the waste drops into the black tank, you can release the foot pedal or handle to close the seal.

Because these systems rely on gravity to force the waste into the black tank, using a generous amount of water is helpful. Regarding solid waste, more water is better. This helps ensure all solid waste goes into the black tank and that there is ample water in the black tank to help dissolve toilet paper and other debris.

Why Does My RV Toilet Stink? 

There are a handful of items you should check if you regularly notice odors in your RV. If the problem persists, you may need to involve a professional to help address the issue. Let’s look at some reasons you might be experiencing a stinky RV bathroom.

RV bathroom
Keeping your RV toilet and black tank clean and clog-free will help prevent unwanted odors.

1. The Vent Pipe Is Clogged

RV toilets use a vent pipe to help release the pressure as water fills and releases from the tank. These vents should vent the air and odors out of the top of the RV. However, animal nests and other debris can clog these vents. A clogged vent will still need to release the air and odors, which usually means it leaks into the RV.

You’ll likely need to climb over your RV to access the vent pipe cover. Remove the screws on the cap and peek into the vent pipe to find any obstructions. A metal coat hanger or other extended and durable items can be helpful in these situations. 

2. There’s Buildup in the Sewage System

If you don’t flush your RV’s black tank regularly, you’ll likely experience a build-up of bacteria. These bacteria can be awful-smelling and may have you exiting your RV in a hurry. However, using a tank treatment and flushing your tanks can quickly eliminate the buildup in your sewage system.

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3. The Bowl Seal Isn’t Working

An RV toilet has a seal at the base of the bowl called a ball seal. This seal helps keep some water in the bottom of the bowl and prevents the rubber parts from drying out. The seal also prevents the odors in your black tank from getting into your RV. Depending on how often you’re using your RV, these seals can last a few years before you need to replace them.

If your toilet bowl isn’t holding liquids between flushes, there’s a chance this seal isn’t working. However, these seals are incredibly easy to replace. Seal replacement is a simple DIY project you can bang out in no time.

➔ Learn how to replace the ball seal and other RV toilet parts here: What Are the Parts of an RV Toilet & How to Replace Them?

RV Toilet Ball Valve Seal Replacement

4. Your Black Waste Tank Is Clogged

Black tank clogs are relatively common experiences in the RV community. Clogs typically result from campers using too much toilet paper, not enough water, or the wrong type of toilet paper. You should only use toilet paper with a septic-safe rating. This helps ensure the toilet paper starts breaking down the instant it touches the water and is less likely to cause clogs.

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Make sure anyone who uses the restroom knows not to use too much toilet paper and that you must use plenty of water every time you flush the toilet. The more water you use when flushing, the easier it is for the contents in your black tank to dissolve. That way, you minimize the chances of having a clog in your system and creating a stink in your RV toilet.

Pro Tip: Keep your RV toilet clog-free by using the best toilet paper options for your camper.

5. Your Toilet Is Dirty

You must regularly clean your RV’s toilet. Plastic toilets are prone to retaining smells, especially from urine. Some RVers have found that after years of using their RV’s bathroom, it smells awful no matter how much they clean. The only way to remedy this situation is to replace the toilet. However, if you clean your toilet regularly or at the end of every trip, you can considerably reduce the chances of your toilet developing odors.\

6. You Are Running Your Bathroom Fan

It may seem counterintuitive but running a ceiling fan in your bathroom when you flush can cause a lot of smell. This is because, unlike household toilets, RV toilets do not have a water trap to prevent sewer gasses from entering the bathroom. Only macerating toilets have traps and tend to smell less.

Our recommendation is to shut or turn off your bathroom fan before flushing. Once the ball valve is closed again you turn the fan back on. This will help prevent pulling sewer gasses into your RV from the black tank.

Pro Tip: Get the inside scoop on What Is A P-Trap? Your Guide To Plumbing That Doesn’t Stink.

How Often Do You Need to Dump Your Black Water Tank?

The frequency you need to dump your black water tank depends on its size and how often you use the restroom. Manufacturers typically vary the capacity of a black water tank for an RV by its size and how many people it can sleep. RVs for families and guests will have larger tanks than those that only sleep two or three people.

Many RVers at campgrounds use the park’s bathroom facilities to make their black water tanks last longer. The more you can use the park’s facilities, the less likely you’ll fill up your tanks. However, most RVs have tanks that last at least a week or more under normal bathroom usage.

Pro Tip: Make dumping your RV black tank easier with these tips on How to Properly Use an RV Dump Station (And Avoid A Mess!)

RV toilet with lid up
Go on the offense with smells and clean your RV toilet regularly to stop the stink.

How Do You Stop Your RV Toilet From Smelling?

If you’re tired of dealing with smells from your RV toilet, there are several steps you can consider. Let’s look at how you can get rid of the odors from your RV toilet.

Use Proper RV Toilet Chemicals

There are numerous RV toilet chemicals like Happy Campers and Camco’s TST Max that can help you fight off an unpleasant stink. These chemicals encourage the growth of good bacteria that will eat away at the bacteria creating scents. Many of these chemicals also have unique fragrances that minimize smells.

The key to eliminating odors is consistency with these chemicals. It’s too late if you wait until you smell your black tank. You should drop one of these tablets or a scoop of the mixture into your black tank after dumping your tanks. Be sure to put a few gallons of water into your tanks to help dissolve the chemicals.

RV toilet mid flush
Use the proper chemicals to keep your RV toilet clean.

Flush Your Black Tank

You won’t get every piece of waste out of your black tank by only dumping your tanks at the dump station. There will likely be pieces of toilet paper and small waste particles stuck inside the tank. Flushing your black tank can help ensure you get the inside of the tank as clean as possible.

Many RVs come with a black tank flush connection. Connect your water hose to a water source and the black tank flush connection. We recommend using a dedicated water hose to flush your black tank and not your potable water hose. While check valves help prevent backflow, do not use potable water to wash your tanks. You should only put potable water into your RV’s drinking hose.

After dumping your black tank, use the flush connection to fill your tanks with clean water. How long you’ll need to let the water run depends on your tank size. However, letting it run for three to five minutes will do the trick in most cases.

Pull the dump valve and watch the water drain from your RV into the dump station. Repeat this process until the water draining from your black tank is as clear as possible and no pieces of toilet paper or waste appear. This can prevent the stink of a black tank from permeating your RV toilet.

potable water sign at campground
Do not use potable water spigots for flushing your black tank.

RV Toilet Alternatives That Don’t Have Black Tanks

Many RVers can tire of battling smells from their black tanks, so they get rid of them. Several options are available, including composting toilets, incinerator toilets, and dry flush toilets. Each has advantages and disadvantages, but the most significant benefit is not worrying about dumping and maintaining the black tank.

These are all suitable options, especially if you don’t want the hassle of finding a dump station. These alternative toilets often allow you to dispose of your waste safely and sanitarily by tossing it in the trash. It truly is that easy in most cases!

Whats so great about RV composting Toilets? | What You Should Consider Before You Buy

RV Toilets Don’t Have to Stink

Don’t let a stinky toilet change how you use your RV. When you maintain it properly, and it’s in good working order, there should be no odors from your RV’s toilet. If you are experiencing smells from your toilet, the suggestions we’ve provided are an excellent place to start.

If you continue to notice odors in your RV, you may need to call a professional. They may have to get into the inner workings of your RV and check things out. A leak in a hard-to-reach area of your plumbing system could be the culprit. Once you address the issue, you can get back to enjoying a pleasant-smelling RV and making memories with your loved ones.

If you think a composting toilet would be just as stinky as a standard RV toilet, think again! That’s just one of 5 Composting Toilet Myths You Need to Ignore.

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About Mortons on the Move

Tom & Caitlin Morton of Mortons on the Move gave up the stationary life for one where they are constantly on the move. They are full-time travelers, television hosts, and digital media producers.
They left their jobs, sold their house and possessions, and hit the road in September 2015 in their full-time “home on wheels”. Since then they have traveled the US, Canada, and even internationally by RV.
Now, they are Discovery Channel & PBS TV Co-stars of “Go North” on Amazon Prime Video, co-founders and instructors of RV Masterclass, and contributing authors for and an Arizona travel guide.

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