RV Toilet Smells When Flushed? How to Deal With a Smelly RV Toilet

A toilet is perhaps the most basic amenity that everyone needs. The call of nature needs to be attended several times a day. Some people don’t mind doing their business in the great outdoors. Others would need a toilet though, and that’s perfectly fine. The importance of toilets in RVs makes it quite a big deal when the toilet smells bad. The toilet might smell bad constantly, or it might give off a foul smell whenever you flush. This is the exact opposite of what the flus is supposed to do, and it indicates that there is a major problem that needs to be dealt with.

The smell might not even be coming from the toilet itself. It might be coming from the kitchen or from any other drain that you have. Depending on where the smell is coming from, various problems might be causing this issue. Wherever the smell is coming from, you would be able to recognize it immediately. It would smell like raw sewage. This problem is particularly annoying if the smell is coming from your kitchen. A kitchen is a place where meals are made, and foul smells of sewage can be a major obstacle that would prevent you from cooking truly delicious meals.

Why Your Toilet Smells Bad

The most likely reason why your toilet smells bad is because a methane buildup. This is the scientific explanation for why this sort of thing is happening. You might need to delve a bit further though. Understanding why this methane buildup occurred in the first place is crucial here. There are four main reasons why this sort of thing might happen. All of these reasons are relatively easy to fix. We will be discussing how to solve this issue below. First, though, we want to talk about the reasons themselves so that you can obtain a better understanding of how your RV’s plumbing system works.

Some Part of Your Plumbing is Clogged

A clog in your plumbing is a very common reason for your toilet smelling bad. RV toilets are not designed to facilitate a large number of people. If too many people have been using the toilet, this might have overloaded it and created a clog. Methane is a gas that is naturally emitted by human waste. Usually when you flush, all of the waste will be taken to the black water tank. However, in the case of a clog this function can’t be properly fulfilled. As a result, the flush only jostles the trapped waste and releases methane from it. This is what might be causing the rotten smell.

The clog might not have anything to do with the toilet either. It might be located in the black water tank. This is the tank that holds all of the waste that you flush down your toilet. Once again, excessive waste might be the cause here. The pipe that leads to your water tank is not that broad. RVs need to have maximum usage of space and minimal weight. A hefty waste pipe, though useful in preventing clogs, would take up too much space and potentially make the RV too heavy as well.

It’s Been a While Since You Have Cleaned Your RV Toilet

You can’t expect your toilet to smell good if you don’t clean it. It’s a repository for waste, after all. Human waste isn’t known for having a nice smell. Even if you flush every time you use the toilet, significant amounts of waste still remain on the toilet bowl. This waste might not be visible to the human eye. However, just because you can’t see it doesn’t mean it’s not there. Eventually, while you might still not be able to see the waste that’s stuck to your toilet bowl, you would definitely start smelling it. It’s not the waste itself that has a bad smell, after all. Not technically at least. It’s actually the bacteria in the waste that cause it to have a bad smell. This bacteria is only visible under a microscope, but they still manage to give off a very pungent odor.

That said, a lot of visual signs might be apparent. If there is a grimy layer on your toilet bowl, you shouldn’t be surprised when it’s starting to smell. This smell would not be exacerbated whenever you flush, though. If that’s what’s happening then the problem probably doesn’t have anything to do with how clean your toilet is. An unclean toilet would smell bad constantly because it hasn’t been disinfected.

There’s a Leak in The Sewage Line

When you flush waste from your toilet, it travels through the sewage line. A break or leak in the sewage line would be the cause of the bad smell. This is one issue that would be associated with flushing. Because waste only goes through the sewage line when you flush. The pressure with which your toilet is disposing of its contents would make waste leak out at a pretty fast pace. Each flush would just end up making the smell worse since it would result in more raw sewage being leaked out onto your floor.

You would be able to discover this problem quite easily. In fact, you might realize that this is the issue even if you haven’t noticed the smell yet. This is because the sewage would be collecting in a very disgusting puddle at the source of the leak. If you see any pools of water that smell bad, that’s your problem right there. Not finding any leaks after checking all of the sewage lines means that some other issue is at play here. Make sure you exhaust all of your investigative options before jumping to conclusions. These kinds of issues are easy enough to manage on your own with basic tools. You don’t want to pay a plumber for something you could’ve done yourself.

Your Toilet Might Be Damaged

If none of the previous problems are causing bad smells when you flush your toilet, the only other possible issue would be that your toilet is damaged. Again, this is not a given. It’s just the most obvious choice when nothing else seems to be wrong.

This is the kind of issue that you wouldn’t be able to fix on your own. A damaged toilet requires plumbing expertise to fix. Attempting to remedy the issue using your DIY skills, impressive though they may be, might just end up making the problem worse. Plumbing is a very complex and challenging beast. It is the prime example of every action having a reaction. Rearranging your pipes in a faulty manner could cause pressure changes in your plumbing system. This could cause a leaking pipe to burst and flood your RV with raw sewage.

It’s best to nip this in the bud and just call someone that actually knows what they are doing. Their charges are usually reasonable and they can fix a myriad of other plumbing issues that you might have as well.

How to Find And Fix Sewage Leaks

The only way to actually make sure that there are no leaks is to check every inch of the sewage pipe. You never know where a leak might be located. Sometimes leaks aren’t so easy to find. If they’re on top of the pipe rather than at the bottom, actual sewage wouldn’t be leaking out. Methane would still be able to escape, though. So you would get the bad smell but would have a tough time finding where it’s coming from. This is why you need to look at the pipe itself, not just the area surrounding it.

One thing that you should never do is jump the gun and just replace your tank. You first need evidence that the black water tank is the problem. A black water tank is not an affordable thing to buy on a whim. They usually cost hundreds of dollars. It would also take a service provider some time to install a new tank. Which means that you would not be able to use your RV while it’s getting fixed up. This is a pretty drastic step to take. Especially if you’re not sure that this is even the issue that you need to deal with.

It would be quite frustrating to pay for a whole new tank only to realize that the issue could have been fixed in a much more affordable, and much more convenient, manner. Usually calling a professional to do some repairs would be more than enough. There is also a chance that the smell might not be caused by a leak at all.  A loose toilet flap can also release a lot of methane. So you need to be absolutely sure before you make any decisions, and hiring a plumber can help you get this level of certainty.

The Proper Way to Clean Your RV Toilet

Cleaning your toilet seems like a very obvious thing for you to do. You might even do it on a more or less regular basis. However, it is important to note that there is a right way and a wrong way to clean the toilet. Proper toilet cleaning is a time consuming process. You only need to a deep clean once every few months, though. A regular bowl cleaning every few days would be enough for regular usage. The following three steps should be considered more of a quarterly deep clean.

Start By Scouring The Black Water Tank

It’s surprising how many people don’t know that black water tanks need to be regularly cleaned. Not cleaning your tank for long enough would lead to a buildup of dry waste. This waste is what will be clogging the tank. A few flushes in quick succession can be enough to break this blockage. Once you have added enough fresh water to the black water tank, let it sit there for a while. Then drain the tank completely. The fresh water added to the black water will have loosened up some of the dry waste. When you drain the tank, much of the dry waste will exit along with it.

Use a Cleaner to Remove Dry Waste

This next step is only necessary if the first one didn’t do the trick entirely. Sometimes there is so much dry waste that a purge and scouring won’t be enough. A heavy duty cleaner should be applied to the walls of your tank. Let this cleaner soak for a bit and loosen the waste up before you start scraping it off. Be careful not to scratch the sides of your tank, though. Once all of the dry waste has been removed, fill the tank up with water so that you can wash the sides one last time, purge the tank once more and then you can start using your toilet normally.

Clear Debris From The Toilet Flapper

If the problem didn’t come from your black water tank, it must be coming from the toilet flapper. You need to clean your black water tank a couple of times a year anyway so that time wasn’t wasted. If the flapper isn’t sealing properly, there might be some dirt or debris that is preventing it from sealing. Use soap, water and a cloth to clear this debris. This should fix the issue once and for all. If it doesn’t, you might just have a plumbing emergency on your hands.

Why This Problem Should Be Fixed Quickly

It can be easy to procrastinate with an issue like this. However, it should ideally be given the highest priority. RVs are very small spaces. A bad smell coming from one area would permeate the whole mobile home in no time. Once the smell has spread far enough it will be very difficult to remove. It’s fair to say that you will never get rid of it until you fix the source of the bad smell first.

This smell is also a health hazard. Human beings aren’t supposed to be mired in the smell of excrement at all times. This air would have lots of germs in it. If there’s a raw sewage leak from one of the lines this could cause all kinds of health issues and diseases. What’s more is that if you don’t fix the problem right away, it’s going to get a lot worse. Your toilet might start overflowing whenever you try to flush it. This is a much more serious issue, one that can be avoided if you just fix the flush problem from the very start. This is one of those things that should never be delayed lest you want some kind of catastrophic failure to occur.

RV Toilet Maintenance Tips

Maintain a Consistent Cleaning Schedule

This is the most important tip that we can give you. Consistent cleaning would make it impossible for a buildup of bacteria to occur. It will also greatly reduce the likelihood of any kind of blockage occurring. You should clean your toilet at least once a month. Try to set aside a specific day during which you will clean your toilets. That way you would know that the day has come and you wouldn’t have anything else planned. The first of the month is usually a good option. It’s easy to remember and gets the dirtiest cleaning activity out of the way sooner rather than later.

Use Special Black Water Tank Cleaners

The waste that builds up in your black water tank is not going to be easy to clean. There are special cleaning chemicals that you can buy that are specifically meant to clean black water tanks. These are very strong and harsh cleaning chemicals so you should make sure you don’t touch them. This cleaner can just be poured into the black water tank occasionally to prevent the waste from solidifying. This would make it easier for you to clean the tank when the time comes.

Add Enzyme Cleaning Tablets to Your Toilet

Enzyme cleaners are a really useful tool. Especially when it comes to toilets. All human waste is organic in nature. Which means that various enzymes will be able to break it down. These enzymes don’t just make your toilet look clean. They eat away any bacteria that might be on your toilet bowl. Hence, none of the bad smell causing bacteria would be on the bowl anymore. These cleaners won’t leave your toilet smelling flowery or sweet. But they will do a good job of neutralizing any bad smells and leave a fresh scent that comes with cleanliness.

Make Sure The Flush Uses Adequate Amounts of Water

A lack of water in the flush can cause dry waste buildups in your black water tank. You need adequate amounts of water that would end up diluting the waste. Otherwise there wouldn’t be enough moisture and the waste would dry out and begin to clump up. If frequent dry waste is an issue, try using more water when you flush. You need to try and find the right balance in this regard. Otherwise you might run out of water a lot faster than expected. Increasing water used during a flush is still important regardless. Not using a lot of water might save a bit in your fresh water tank but it might create more problems than it solves.


What kind of toilet paper should I use in an RV toilet?

Using regular toilet paper is a common mistake. RV toilets aren’t built to handle such things. They will most definitely clog up your toilet. If you have been using normal toilet paper, this might be the reason for the bad smell. You can only use septic safe toilet paper in an RV. This will break down a lot easily in the septic tank.

Should I clean my black water tank once a year?

This is usually sufficient although you might want to bring it up to twice a year. There’s no harm in doing it more frequently either. What you shouldn’t do is let the waste sit in the tank. It will fester and rot and inevitably a blockage would occur that would release a very foul smell into your RV. Emptying it out before it gets full is a surefire way of preventing bad smells when you flush your toilet. Make sure that you use the right kind of cleaner in your black water tank. Regular cleaners just aren’t strong enough to break the dry waste down. If you empty the tank out quarterly, though, no dry waste will form so regular cleaners can work just fine.

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