If you are in the middle of a camping trip and you are finding that your RV smells like sewage it can be quite unpleasant, but what is the source of the odor?

RV campers require a considerable amount of work to stay operational, which means that sometimes you have to get your hands dirty and deal with your vehicle’s sewage system. However, there are actually a number of different reasons why your RV camper can smell like sewage - with some being considerably easier to fix than others.

Your RV camper most likely smells like sewage due to your tank drainage hose, dry P-trap, sewage leak, inadequate ventilation, or damaged plumbing. The best way to prevent sewage smells in your RV is to regularly clean your sewage system and all of its equipment.

When it comes to traveling around the United States, there is no better way to do it than in an RV. If you are like so many folks, then you know that RV travel is a way of life, as it offers such a homey and dynamic experience on road trips. However, owning an RV is going to require that you take care of it properly if you want to maximize its lifespan - and there are a lot of things that are easy to overlook. At the end of the day, you should approach your RV in a similar way that you do your own home, which is why you most certainly do not want it smelling like sewage. One of the worst situations to find yourself in when on the road is having an RV that stinks like sewage - with no clue where the smell is coming from. This can be particularly frustrating if you have already crossed all of the logical possibilities. To help you identify why your RV stinks like sewage, we are going to take a closer look at all of the possible sources of the smell.

After extensively researching RV sewage systems and upkeep, I have been able to gather enough information to determine why your vehicle is likely experiencing this foul odor. My research has shown me that the best way to prevent your RV from smelling like sewage in the future is to keep all of your systems and equipment clean, contained, and maintained.



Where Do RVs Store Sewage?

Your RV is a highly-sophisticated piece of machinery and it has an advanced sewage system that is quite similar to the one in your home. However, unlike your home, your RV’s sewage does not flow into a city-wide septic system - with a simple flush taking care of all of your problems.

Just about every RV has a septic system that has a black and gray water tank. Both of these tanks are responsible for storing all of the waste from your RV. However, understanding the difference between these two tanks can greatly help you eliminate your chances of experiencing foul sewage odors in your RV camper.

Black Water Tank

If the cause of the sewage smell in your vehicle is coming from any of the tanks, it is definitely going to be your black water tank. Your black water tank is the part of your RV’s sewage system that holds all of your toilet waste.

Gray Water Tank

Your gray water tank, on the other hand, is not going to be responsible for the sewage smell in your RV, as this holds all of your vehicle’s drain water such as from your shower and sink.

However, how you drain your gray water tank in combination with your black water tank can potentially be an indicator of the smell. More on this later.

Sources of Sewage Smell

If you are entering your RV and finding that the whole place smells like sewage, you are going to want to find the source of the stench and eliminate it as quickly as possible. The tricky thing with these situations is that there can be any number of factors contributing to the problem, which is why you want to be thorough and tick every box. Let’s dive into the sources of your RV’s sewage smell.

Tank Drainage Hose

The most common reason why most people’s RVs start to smell like sewage is due to a dirty tank drainage hose. When you drain your black and grey water tanks, you need to keep in mind that all of the sewage that was in your vehicle just passed through your tank drainage hose.

It should not come as a surprise that your hose can end up stinking from time to time, which is why it is best to keep it as clean as possible in between uses. If you are draining your tanks properly, you can greatly avoid it smelling but everyone needs to clean their hose from time to time.

To clean it, simply spray it with some soapy water and/or a cleaning solution such as bleach. This will greatly reduce the smell and it will also disinfect any bacteria that has built up in the hose. You must have an adequate storage container for your hose. A lot of people use simple net bags for their hoses but this is asking for trouble. Instead, get yourself an air-tight container or, even better, an official container designed for RV sewage hoses like this one.

In addition to your hose, you should also follow a similar procedure for all of your sewage equipment. You likely have an elbow adapter that also gets used when you drain your sewage. This can end up with foul odors if not cleaned and stored properly, which is why it is best to have an organized and contained system for all of your sewage equipment.

Dry P-Traps

This one can be quite easy to overlook and it is one of the main reasons why so many RV travelers deal with sewage stench for days on end without figuring out what the cause of it is.

Your RV has a P-trap - much like your home. However, RV P-traps are known for drying out much more often than domestic ones. Your P-trap is the shape of your sewage pipe that connects your RV’s toilet to your black water tank (it is shaped like a sideways ‘P’). This can easily dry up, which results in waste building within the pipe and drying up. In addition, it is likely leading to airflow from your black water tank directly into your RV.

There should be a small pool of water that sits inside of this pipe which creates a liquid barrier between your black water tank and your RV - preventing any odors from coming in. It also keeps water constantly in your pipe which adds to cleanliness overall. This is a particularly common occurrence if you have not used your toilet in a while - especially when you first start your trip.

If your P-trap is dry, simply take about a half-gallon of water and pour it inside of your toilet. This should fill the trap and create a water barrier. We also find that using a cup of vinegar helps with the process of preventing it from drying up.

Inadequate Ventilation

Your RV is going to feel much nicer if you have got proper ventilation moving through it. This is a common reason why RVs start to smell like sewage and it is usually a very simple fix.

Unless there is a more serious underlying problem, your RV may just smell because you do not keep your windows open enough or use your ventilation system routinely. If you are finding that your RV starts to smell like sewage immediately after you have used the bathroom, then you probably just need to air the place out a bit.

A lot of RVs have windows or vents inside the bathroom itself. If yours does, open them during and after your bathroom use. In addition, your RV should be well-equipped with vents and windows throughout the vehicle - use them regularly to keep proper ventilation flowing.

Sewage Leak

If you have tried the most logical approaches, then you could be in store for some legitimate repairs. A common reason why RVs start to smell like sewage is due to leaks. Much like your home, your RV is subject to leaks. And as unpleasant as they are to deal with - it’s part of owning a recreational vehicle. Sewage leaks are a bit more problematic than common odor sources, as you will likely need to do some maintenance work on components or have a specialist take care of the issue for you.

The first area that you want to check is your wastewater valve. If you are finding that there is any sign of a leak or a smell coming from it, then you have found your source. This is not all that difficult of a process to fix, as you should be able to get the job done on your own. You will, however, likely need to buy a new wastewater valve like this one.

A sewage leak can be considerably more challenging if you happen to have a punctured black water tank. This is usually not a fix that most RV owners can handle on their own, which is why it is probably going to be best to see a service station in this situation or have the tank replaced entirely (depending on the severity of the damage).

Damaged Plumbing

A really tricky fix to solve is if your RV sewage smell is coming from damaged plumbing. This can be due to any number of issues and they may require you to seek professional assistance from a service shop - unless you happen to be an experienced plumber.

Damaged plumbing can occur be caused by old/ruptured seals, cracks in pipes, or punctures. To start, you should have a look at whatever pipes you can get access to from your sewage system and keep an eye out for any leaks.

If you see any sign of a leak, then you have found your source. This can occur from simple wear and tear over time or it could be the result of your vehicle snagging a rock or some kind of debris on the road. However, damaged plumbing is particularly common due to RV owners failing to winterize their RV. When you forget to drain your fluid systems before outside air temperatures drop below freezing - you run a serious risk of your pipes bursting, which results in damaged plumbing that, more often than not, needs to be replaced entirely.

How to Prevent Sewage Smells

If you have found the source of your smell and want to avoid experiencing it in the future, you should take proper preventative measures to contain sewage odors. However, there is no one-stop-shop to guarantee this, you have to take an all-around approach with your RV camper if you want it to stay clean, sanitary, and functional. Let’s dive into how to prevent RV sewage smells.

Regularly Drain Black Water Tank

If you want to avoid unpleasant odors and unnecessary sewage upkeep/maintenance, then you should be draining your black tanks regularly. A lot of people neglect their black tanks and put off draining them until the very last minute. This is not the way to keep your RV from smelling like sewage.

When you let your black tanks build up with waste, the chance of that smell spilling over to your RV is going to be much more likely. To avoid this, simply make a habit of draining your black tanks routinely. However, this is not something that you need to turn into a tedious chore.

The general rule of thumb is that you should be draining your tanks every 5 to 7 days - depending on how often you use your toilet and how large your tank is. If you want a more precise approach, then you should drain your black water tank when it is 50 to 75% full.

Flush and Clean Toilet Regularly

‘If it's yellow let it mellow’, is not a sanitary RV practice - and it is not going to help your RV smell any less like sewage. If you use your RV toilet - flush it. And flush it good! Make sure that you hold your RV flush button enough to let enough water drain into your pipes and tank. This is not only going to enable better flow through your pipes but it will also help keep your black water tank from building up solid waste.

In addition, make cleaning your toilet a regular part of your cleaning routine. Just like at your home, if you neglect your toilet, it is likely to start getting pretty foul as well. Invest in some adequate toilet cleaning supplies and use them as needed. We find it is best not to wait until the last minute for when things start to get gross. Instead, clean your toilet once a week. This is especially an easy habit to form if you do it whenever you drain your black tanks.

Lastly, it pays to do a thorough toilet and septic cleaning from time to time, which is when chemical deodorizers come in handy. Just drop one into your toilet periodically to seal the deal with your cleaning.

Drain Gray Water After Black Water

A very common reason for sewage smells is due to people draining their black water tank after their gray water. This is a big no-no in the RV travel world and you are setting yourself up for a smelly camper if you forget this simple method. The reason for this is that your black water tank will be the last thing to make contact with your sewage hose and equipment - meaning that everything that just passed through your tank is going to linger around in your hose.

Always drain your black water tank first! After you drain your black water tank, your gray water is going to take care of the majority of the cleaning for you. As the gray water passes through your hose and equipment it will flush just about everything out. That is not to say that your gray water is clean by any means but it is going to be a lot nicer to deal with than your black water.

Install Ventilation

Not every RV is equipped with adequate ventilation, which is a common problem with a lot of older RVs. If you are finding that there is a lack of airflow in your recreational vehicle, then we would highly recommend that you install at least some kind of ventilation inside of your RV.

There are a number of ways that you can go about this but the best would be to have a window or a vent inside of your bathroom, as well as other parts of your RV. The more airflow points that you can open up in your RV camper, the less likely you are to experience unnecessary sewage smells.

However, if this is not an option for you, then you should make do with what you have. Virtually every RV has at least some kind of ventilation system in it. There will be vents, windows, and doors all at your disposal to encourage proper airflow - use them. In addition to natural airflow, you can also use your RV’s air conditioning system with just ‘outside’ air enabled to let a quick breeze through.


Anthony Day

Anthony Day

Hi, my name is Anthony, and RVs are what I'm passionate about. I bought my first RV when I was 21, and I've been hooked ever since. I'll guide you on how they work, how they can be used in different environments, and how they fit into our everyday lives.

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