Nothing is worse than a sewer smell outside of your RV. Solving the problem is more than an annoyance, it can also be a sign of a serious problem. While the sewer smell in RV life is usually coming from an inside source, there are times when you might be relaxing under your awning and realize the great outdoors don’t smell so great, and your RV is the problem. A persistent sewage smell outside your RV is enough to ruin the home-away-from-home mood for anyone. Determining where it’s coming from and how to prevent it are the key to your RV happiness.
Why does the outside of my RV smell like a sewer?
The top reasons your RV might smell like a sewer outside are:
- Too little water in your black water tank.
- A full grey water tank.
- An overcharged battery.
- Leaking sewage pipes.
- The grey tank valve is open.
- You have a propane leak.
We will go through the possible origins of a sewer smell outside your RV and potential fixes and preventative measures. They range from benevolent to severe enough to cause significant problems on the road. Knowing where to look and what to do can save you time and hassle in alleviating sewage-like smells around your RV.
We have consulted the RV community and forums to bring you the best guide on tracking down an outside sewage smell because, after all, no one knows better than those who have been there before.
Why Does It Smell Like A Sewer Outside
Most knowledgeable RVers know that the sewer smell is usually found inside the RV due to valve issues in the bathroom or sink area. However, if it comes from outside of your RV, there are a few origin points that should be checked.
Assessing the situation and knowing how to remedy it will help keep everyone happy underneath the awning at happy hour!
Too little water in your black water tank.
It might be counterintuitive, as a full black tank seems like it would be a more likely culprit than an empty one when it comes to smells, but having little to no water in your black tank can cause a sewer smell outside of the RV.
When operating on a pump-out schedule alone, only the minimum is being down, a proverbial surface flush of contents. However, your black tank needs regular maintenance in the form of pressure washing the side walls and disinfecting regularly. When the tank becomes empty, there is no water barrier to contain the sewage vapors. The smell then tends to migrate up the vent stack into the RV and further out the vent in the RV to the surrounding outside air.
The Fix: Don’t fall into a lazy habit of emptying the black tank without maintaining it. Pressure wash and disinfect the black tank on a regular basis to prevent build up on the side walls and eventual vapor buildup.
A full grey water tank.
A full grey water tank with open valves can give an off foul smell. While most people think of the black tank as the problem child, the grey tank can be just as bad, harboring build-ups of hair, food waste, grease, oil, toothpaste, sand, and dirt.
These things, combined with bacteria, can entice a mold build-up on the interior and create an aromatic problem.
The Fix: While emptying your tanks periodically will eliminate the waste and some of the smell, the dark damp environment is perfect for mold to continue to thrive. Get regular periodic tank cleanings done professionally. In between professional servicing, you can use a DIY blend that Kleen Tank recommends of Calgon, Pine Sol, and water.
To do this, mix 40 ounces of Pine Sol with water to just about full in a gallon jug. Top off with a half cup of Calgon. Use 8 ounces in each tank or more if it is sweltering out or if your tanks will fill up slowly over time.
An overcharged battery.
An overcharged battery might not be your first thought regarding an outside sewer smell, but it is worth ticking off the list on your search for the sewage smell origin. This is likely the culprit if you follow your nose to the battery housing area. Overcharged RV house batteries can give off a rotten egg smell.
Overcharging can cause the batteries to overheat when the charging voltage from the converter is too high.
This can also happen when too much current is being drawn away. Overheated batteries can cause the acid to boil and emit rotten egg like fumes.
A sulphuric smell from your RV battery can also be a sign that something is awry and that it is no longer able to charge effectively. Leaking acid will also cause this smell and can cause the battery housing to melt.
The Fix: The good news is that RV batteries are relatively easy to replace – you might even have a spare on hand. Preventatively ensure your RV battery’s water levels are always topped off. Also, try to keep your battery fully charged to maintain its health.
Leaking sewage pipes.
Leaking connections from the bathroom to the black tank can definitely cause an outside sewage smell. You can visibly follow the lines to the black tank and look (and smell!) for any evidence of a compromised seal, valve, or connection causing a sewage leak on the way to the black tank.
The Fix: Repairing a sewage line might not be top of the fun maintenance list, but it is a relatively easy fix. You’ll need a special two-part epoxy suited for ABS plastic or a product like Plasti-Mend, which contains a special mix of plastic resins and solvents designed to bond to the surface of the offending leak area. Then, dry the area thoroughly, apply the patch, and you should be back in (less smelly) business in no time.
The grey tank valve is open.
The grey tank valve is also a place where sewer smells can escape from when full or if there is a build-up of sludge and mold.
The Fix: Instead of leaving the valve open, try closing it off until it is time to dump the contents of your grey tank. If this is too troublesome, you can make a DIY vent by making a trap in the sewer hose. Place the sewer hose under an object and raise it up high enough to create a P-trap that will keep some water in the bend and unsavory sewage smells and flies out.
You have a propane leak
Your nose just might save the day on this one. Propane leaks can smell like rotten eggs. Natural propane is actually odorless, but manufacturers add a sulfur smell for safety purposes so people can detect potential leaks.
While a propane leak detector will let you know this is the case inside your RV, your nose will have to be the detector on the outside.
Check your propane gauge and see if there has been a sudden dip.
The Fix: If you are even suspicious there might be a propane leak, turn the gas off immediately by shutting off the LP valves and have everyone evacuate the RV. Extinguish any pilot lights inside the RV. Call a propane service professional immediately to determine if and where the leak is coming from.
The truth is, a sewage or rotten egg stench can come from several areas that affect your peace and harmony outside of your RV. They range from less serious black tank leaks to more serious battery, propane, or mold issues. So follow your nose because it just might save you from disaster on the road.