The first step to eliminate RV odors is to determine what is causing the odor. Evaluate the odor. What does it smell like? Are you smelling the Honey Bucket at the fair, or maybe rotten eggs? These are clues that will help you narrow down the cause.
RV Odors From the Black Tank
There are a couple of other things that could be causing the black tank smell. If you open the basement access door on your RV and detect a foul odor, it’s likely coming from your gray or black water holding tank. This is especially true if you have recently emptied your tanks, as you smell waste left in the tank (and on the tank walls). If this is the case, it’s time to do some deep cleaning.
How to Get Rid of Black Tank Buildup
There is a gasket that seals off the toilet bowl from the black tank. The proper name is flush ball seal. That seal can wear out or get fouled with debris and will make room for some airflow from the black tank into your bathroom. This is especially true when your vent fans are running.
Replacing the seal is quick and painless but I would recommend flushing your black tank really well before starting the process to keep the odors as minimal as possible. This video will guide you through changing the seal. RV Toilet Ball Valve Seal Replacement
If you are dumping your tanks at a dump station try to find one that has flush water available. It’s not absolutely mandatory to flush your black tank after you dump it but it really helps keep those odors in check. It also helps avoid buildup in your black tank which can lead to a clogged tank.
P-trap Odors
A p-trap is a curved pipe under your sink or shower. It holds water to stop smells and sewer gases from coming up through the drain.
When I was new to RVing I was surprised to learn that p-traps can put off a smell remarkably similar to a sewer. I’ve learned to sprinkle a little black tank treatment into the p-traps in my sinks and shower occasionally.
I use Happy Camper RV Tank Treatment and it works really well.
This also occurs if you stay parked for a period of time without running water through these pipes. The p-trap dries out and the odor becomes strong. The cure is the same, run cold water for a few minutes and then add some RV holding tank sanitizer to the p-trap. RV odors eliminated!
Dead Mice, Other Rodents, or Birds
If you are smelling something like decaying flesh, there is likely a decaying rodent or bird in your RV somewhere. A fellow camper had a mouse die in the ventilation ducts above their bed. It was not pleasant. If you have this nasty odor in your RV, air your RV out as much as possible. If you can’t find the source, you may have to live with it for a while. It will eventually go away.
Check Your Batteries
If you smell rotten eggs it may be your batteries. If you have standard lead-acid batteries they may have gone dry. Overcharging batteries will cause them to boil and the sulfuric smell resembles rotten eggs. In this situation, your charger is likely overcharging the battery, which will cause damage to the plates inside of your batteries. If you do not check and properly maintain the fluid levels in your batteries you will damage your batteries.
Why does rotten egg smell occur? Sulfuric acid (the electrolyte in a lead-acid battery) is a weak acid and sulfur dioxide gas is produced in the case of overcharging, thus the smell of rotten eggs. What to do: If the smell is indeed coming from your batteries, they will likely need to be replaced.
It is important to know what odor you are dealing with first. Some black tank odors can be eliminated by cleaning your black tanks and adding black tank treatment while others may require a new flush ball seal. For those rotten egg smells, you should check your batteries right away. If the smell persists, don’t hesitate to contact an expert for advice!