RV Toilet Smells When Flushed : Reasons & How To Fix It

That mucky smell looming inside your RV is not something you want to carry along right?

While you ram around in your trailer, sometimes you forget to pay attention to the maintenance of your toilet space; until the need arises.

This could be problematic, especially if you are a newbie owner and don’t have much idea about dealing with the smelly factors.

So, let’s dig deep and find out where you are getting wrong in your toilet usage inside RV.

Generally, the unwanted smell creeps out, when you don’t flush properly or when something goes wrong with your toilet system. Let’s figure out the reasons.

Reasons why RV toilet smells when flushed

An RV toilet is not very complex to maintain, but there are plenty of reasons where you could go wrong. As you would know RV toilets could be liquid-based or dry.

Liquid-based uses water and chemical treatment to break down the waste. But some toilets like compostable ones, function without using water.

They claim to have an odor-proof system that ensures no leakage of foul smell, but if not maintained properly, they will not contain the stinky methane smell.

So, you need to find the source of the smell first. This lingering foul odor could be a result of clogs or buildups or leaks. Let’s get to its bottom.

1. Tank buildup

Your black tank or waste holding tank is designed to hold waste up to a certain level. Beyond that, it won’t be able to hold. So, frequent dumping of waste is mandatory.

Large blocks of solid buildup could float in the tank or stick on the walls if not cleaned well. These blocks may be a gritty combination of toilet waste and wet toilet paper.

To avoid this hassle, clean and sanitize your tank every time you empty it with bleach or strong cleaning agents. Pump water into the tank using a hose and make sure that there is no residue left.

2. Presence of clogs

Clogs present in the toilet is the root cause of many RV toilet problems. They are formed by the build-up of solid blocks inside the toilet.

This could be due to dumping toilet paper carelessly into the bowl or by not flushing well. It will stick to the end of the tank and block the pipes and tubes connecting the bowl and black tank.

Therefore, black tanks become the epicenter of this smell. Sometimes it won’t let the water flush away smoothly. It keeps water from flowing through pipes.

3. A potential leak

There is a high chance that your toilet is leaking somehow. Sometimes the tubes must be damaged or the tank might have damaged due to cracks and holes in it.

Or the sewer lines are damaged somewhere. In this case, you might need a good plumber to solve this problem.

You need to figure out the reason since it might not the visible at the first look.

Get it checked with a plumber and fix it as soon as possible. Or else, you will find unwanted sewer waste floating in your toilet space along with a foul smell. And the black water would be difficult to clean.

4. Lack of maintenance

Cleaning your RV toilet once in a millennium won’t do the trick. A sticky, unclean toilet will release stinky smells.

You will get uncomfortable soon enough. Moreover, it will degrade your RV’s cleanliness and turn the pleasant fragrance mucky.

A lot of potential buildups can be avoided when cleaned properly. Also, replace the damaged parts of your toilet if the need arises.

So, clean both inside and outside your toilet, to leave it squeaky clean and hygienic. Use suitable brushes or sponge according to the material of your bowl.

5. Lack of ventilation

If you don’t have proper ventilation in your RV the diffusion of toxic gases would be difficult. The fresh air won’t get inside and get rid of the stuffy smell.

So, check if your RV toilets have proper air vents. Sometimes, they might get blocked due to the presence of dirt and dust. In that case, clean it well.

How to get rid of RV toilet smells when flushed?

To let in fragrance inside your RV drowning all unwanted smells, you will need these tips.

As you already know, flushing is the easier part, and clearing the tank is the hardest. So, here is what you need to do to avoid smelly, clogging toilets.

Buy a waste odor neutralizer. It works like magic. It will eliminate the foul odor as well as digest the waste.

Also, clean the toilet every time after you use it. You can add some bleach along with the flush water to serve this purpose.

Always keep a strong toilet cleaner handy and use it frequently. Pour it into the toilet and let it sit for a couple of minutes.

Then scrub it thoroughly using a sponge and rinse it well. Do not forget to clean the dry waste stuck in the corners as well. It will keep the smell at bay.

Find and remove small clogs immediately before its condition worsens. Big clogs could block your entire toilet system.

The buildup formed by toilet paper and toilet waste should be removed as soon as you know about it. It could also be a result of not cleaning the toilet regularly.

Apart from the black tank, clean your gray water tank too.

Even though it is not directly related to the toilet waste, it also contains leftover water from the kitchen and shower. And this could also add up to the foul smell if not cleaned regularly.

Make sure that your toilet is well-ventilated. The vents will let in the fresh air and release the stuffy smell outside. Thus, the sewage odor won’t linger inside your rig for long.

Another tip is to replace your black tank if it is damaged. There could be cracks and holes inside that lets out the bad smell.

Check its condition first and buy a new one if necessary. It might cost you around $500 to $800. But in the long run, you can’t avoid this expense.

When you figure out a potential leak in the inner plumbing’s, make sure that you close the toilet flap tightly. Or else the foul odor will leak into your RV.

Flush your toilet multiple times after using it. Thus, the waste will reach its right destination and ensure that no dry buildup is left inside.

You can also hold the foot pedal down for some time. This will add an ample amount of water to cover the waste and reduce its odor.

Water is a good cleansing agent. So, the more you use it for cleaning, the better. But do not drain your freshwater supply in this account. Use gray water instead.

You know that using gray water would save your freshwater consumption. But make sure that you have a gray water recycling system fit inside, to ensure the black water is recycled and filtered well before releasing it to the tank.

The toilet flapper is another part that you need to pay attention to. It is present at the bottom of your bowl and serves as a seal between the toilet bowl and the holding tank.

If it is not working well, there is the chance that waste particles might get trapped inside it. So you should replace it if is cracked or worn-out. Never think twice before replacing a leaky flapper.

Clear the contents of the black tank as frequently as possible. As you would know, the lighter and cleaner the tank, the better.

So, when you hit a campsite, check with the authorities, pay the necessary fees, and dump it away.

Clean the tank thoroughly after this using bleach or other chemicals. Then you are good to repeat the cycle without the fear of leakage.

You can also try a bacteria-based treatment to replace anaerobic bacteria with good aerobic bacteria.

There are bacteria digesting enzymes available in the market. This is a good alternative if you are not a big fan of using caustic chemicals for cleaning.


I hope that you have a good idea about keeping your RV toilets odorless now. As I have mentioned earlier, you need to take care of your RV toilet very well.

Clean your toilet regularly, and when you do use masks and gloves, for protection. In addition, you can spray your favorite deodorant or room-fresheners to suppress the sewage odor.

You can also keep scented candles or potpourris inside your RV for the same. Keep the air vents open whenever possible for the fresh air to gush in.

Finally, pay attention to every nuance and take action on time. Don’t wait for the worst to come. If you have any additional tips on how to keep your RV odorless, leave it in the comment section below.