Why Does My RV Smell Like Sewage? Perfect Way To Fix It

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The thing about RVs is that it is a great way to enjoy nature while still having some of the comforts of home thus it has over time become a popular way for people to go camping.

Now, unlike in a house, where waste from the toilet, shower, and sink can be flushed or washed away, in an RV, waste stays in its belly for days or weeks at a time.

During this time, smells from whatever went down the drain can come back up into the RV living space. This makes a trip that would otherwise be fun something else but above all discomforting as your relaxing vacation will come to a screeching halt when you get back to your camper and it smells like sewage or rotten eggs.

When that sewer smell hits, how can you even manage to enjoy camping especially if that smell is everywhere?

The good news is that this smell is easy to fix most of the time and can be fixed in a short amount of time and you could be able to breathe deeply again. You might not even have to spend a dime on expensive cleaners or fixers as this can even be done with what you already have.

Why Does My RV Smell Like Sewage?

Since preventing this smell is cheaper and in most cases easier than having to take the smell out, it is important that you know exactly why your RV would emit such an offensive smell in the first place. This is at best very crucial in preventing it from happening again. Let’s start with the most important reasons.

An unclean toilet: If you keep up with maintenance and everything seems to be working, the answer might be as simple as making sure the toilet bowl is clean. Just like a house on the land, toilet bowls need to be cleaned so that waste and smell don’t get stuck in them and spread to other places where people live since some RV toilets don’t have water in them, so a dirty toilet could be the cause of the smell.

More so, open valves can just be responsible for this smell, the problem is that if you leave your grey tank or black tank dump valves open (even when you are hooked up to a sewer system at an RV park), the sewer smell from the RV park’s sewer system could get into your RV and make a smelly mess. Because these vapors are dangerous, you should never leave your tank valve open.

The thing is that if you leave your valve open, you could also let human waste build up at the bottom of your black water tank. The liquid will go straight into the sewer system, and the solids will stay behind and make a bad smell that will also get into the trailer. Thus make sure your valves are always closed, and you won’t have to deal with an unpleasant smell.

So what happens if after these basic checks and your RV still smells like sewer, it’s often because there isn’t enough water in the sewer tank. Unbelievable right? Well, the thing is that the waste in it needs to be mixed with enough water to keep it from drying out.

As a general rule, holding tanks should be dumped and flushed when they are between half and three-quarters full. Once the holding tanks are empty, you should close the dump valves and pour about two or three gallons of water into each one.

This way, the water at the bottom of each tank will dilute any waste that goes into it in the future. Make sure to put a deodorizer and treatment in each holding tank as soon as you put water in it.

Interestingly, If your RV smells like sewage, there is a less likely cause that has nothing to do with sewage as the smell could be coming from your RV’s house batteries being overcharged, which would cause the electrolytes (battery acid) to boil and give off a smell like rotten eggs or sewers.

To make sure this is the problem, you can check the house batteries’ electrolyte levels by topping them off with distilled water. If they are full and seem to be boiling, if this is the case, you should have a Certified RV Technician look at the house battery charging system.

Tank smells and hot weather doesn’t really go together well. Bacteria are much more likely to stink up the place in the summer. Even if you take care of your camper’s tank treatment to the letter, it might still smell bad.

Lucky for you, I just found out that there are products that are made to take care of your tanks in the summer and winter, hence, the next time you go shopping for a tank smell remover, just make sure to get one that is made to work in high temperatures.

How to Get Rid of the Smell from an RV Holding Tank

Having seen some of the reasons why your RV would most likely smell, it is now for you to know how best to keep this smell away. To begin with, ensure RV tanks from getting clogged. To keep a tank in good shape, the first step is to keep it from getting clogged.

The best way to do this is to only use RV-safe toilet paper when you go to the bathroom. Don’t put toilet paper down the toilet at all if you can help it. Do what people do in places with sensitive plumbing and throw it away.

Then you have to make sure the tank has plenty of water. This is so because if the black tank always has a lot of water in it, it will be much easier to avoid clogs and smells. Toilet waste needs to be mixed with water so that the solids in the tank don’t dry out and make smells. This can be done in a number of ways.

One way is to flush the RV toilet every time you use it. And if your deposit was big, putting a little more water down the toilet drain can also help. Also, when you add water to the tank, you should make sure that the water covers the bottom of the tank completely.

You can check this with the black tank sensor or make sure to flush about four to six tanks of freshwater down the toilet.

Furthermore, to cut down on smells, even more, make sure you empty your black tank before it gets full. This will need another check of the sensor for the black tank. Plan to empty your tank when it’s about 3/4 full. When you empty the black tank, it’s a good time to give the tank a good, if not thorough, cleaning. 

The RV toilet gate valve is the only simple part that keeps smells from coming up into your RV bathroom. This valve (or flapper) must be kept clean and in good shape at all times.

The seal around the valve is also important because it keeps a small amount of water in the bottom of the toilet. This water will keep any smells in the toilet or tank from coming back.

Do you know that If the toilet’s gate valve is dirty, it might not close and keep that seal tight? Well, now you know, hence use a wet cloth and wipe around and under the valve to get rid of any dirt or dust. This is also a good time to look for cracks in the valve seal.

Finally, Happy Campers RV Holding Tank Treatment is one of the best products for treating tanks and getting rid of smells. Minerals and micronutrients in the treatment treat waste and get rid of smells without using perfumes. One scoop is enough for a 40-gallon black tank, and the product will also work fine in your grey water tank.

Well, in my search for how best one can get rid of RV smells, I came across the Geo Approach, a very wonderful means of getting rid of this smell too which is also a popular way that a lot of other RVers testified to. For this method, you only need two things.

And it is simple, you just Pour one cup of each into your toilet every time you empty your black tanks and close them. Then fill your toilet with water and flush. The last step is to add three more gallons of water and flush the toilet again. Almost every time you do this, the result will be a fresh, clean smell.


In the end, I have tried to show what could be the cause of the sewer smell in your RV. But then note that sometimes the cause of the bad smells is too big of a problem that it’s best to leave it to the experts.

I know this can be hard to accept, but if you try to do a hard job yourself, and you did not do it well, you might make a bigger mess and have to pay more to fix it. Thus, I hope this article helps you figure out why your RV smells like a sewer and guides you enough to find a lasting solution to it.

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