Why Does My RV Smell Bad?

When staying in an RV, you can experience great scents of the outdoors like pine trees, or the salty ocean breeze. However, things can take a turn when you start noticing that your RV is making unpleasant sewage or trash smells. So why does your RV smell bad? 

Bad RV smells are typically due to such common problems like: a faulty water heater or electrical system, an overcharged battery, leaking propane, a full black or gray tank, a defective toilet seal, leaking fridge coolant, pests, or mold.

Now, let’s dive in to why your RV smells a little funky, and how to get it smelling fresh.

The Water Heater System Has a Problem

Sometimes there is a strong smell of rotten eggs in your RV when you run the water. The culprit is often the water heater, as most RV water heaters have an anode rod inside a steel water tank. 

When the magnesium and sulfur on the anode rod react with bacteria from the tank, the reaction produces hydrogen sulfide gas.

This gas contributes to the rotten egg smell in your RV.

What To Do About a Problem With the RV’s Water Heater System

If the nasty, rotten egg smell in your RV is because of a problem with the water heater system, you could do the following:

  • Clean the water heater system thoroughly. You can use water and hydrogen peroxide to clean the water heater system as the solution helps get rid of the smell. Lemon juice can also remove the smell and create a fresh citrus scent.
  • Replace the water heater’s anode rod. You can replace the existing anode rod with zinc or aluminum to prevent a bad smell in the future. 

There Might Be Propane Leakage

Many RVs use propane as the source of power. Although propane is odorless, propane suppliers add a substance that smells like rotten eggs to help you detect leakage. You can also experience the smell of rotten eggs when the propane is running low.

What To Do if Your RV Has Propane Leakage

Propane is a volatile gas, and if you suspect the rotten egg smell is due to propane leakage or low propane levels, do something about it quickly. 

Here is what you can do:

  • Check if your propane is running low. Refill the propane cylinders if the propane is running low. Once you refill them, the smell of rotten eggs should go away.
  • Check if the propane gas is leaking. If you suspect the propane gas is leaking, switch off the propane system. Call an expert to check the propane system as leaking propane is dangerous. 

Your RV Batteries Might Be Overcharged

Lead-acid batteries power the engine of your RV. Sometimes, the RV’s lead-acid battery becomes overcharged and produces a gas that smells like a rotten egg. The smelly gas could become hazardous to your health and is also flammable.

What To Do About Overcharged RV Batteries

If the foul smell in your RV is because of overcharged batteries, it is best to call a professional. An overcharged RV battery could become flammable and thus poses a risk to you and your RV. A professional can diagnose the problem and advice you accordingly. 

The Black Tank Is Full

If your RV has a toilet, you might occasionally experience a distinct sewage smell. There is a black tank attached to the RV’s underbelly, and all waste from the toilet goes into this tank. If the sewage smell persists, you haven’t emptied and cleaned the black tank as required.  

What To Do About a Full Black Tank

If the smell in your RV is due to a full black tank, you should do the following:

  • Empty the tank immediately. Emptying the tank immediately into a designated dump site is essential.
  • Clean the black tank. Use water, a cleaning wand, and a simple all-purpose cleaner to clean the black tank thoroughly.  
  • Put water in the black tank. Once your black tank is clean, put in some water, which can help reduce the odors.
  • Add some black tank chemicals. The black tank chemical helps eliminate odors and helps break down the waste. 

The RV Toilet Seal Is Faulty

If the sewage smell in your RV persists after emptying and cleaning the black tank, then there could be a problem with the RV’s toilet seal. When the toilet seal is faulty, water mixed with waste leaks onto the RV’s toilet floor. As a result, your RV can smell like poop and urine. 

What To Do About a Faulty RV Toilet Seal

When the toilet seal is defective, you should replace it immediately. Replacing the toilet seal prevents smelly water from seeping into the RV’s toilet floor, and the foul smell will thus go away. You can replace the seal on your own or call a technician. 

The Gray Tank Is Dirty

All the waste from the sinks and showers in the RV goes to a gray tank. When the gray tank becomes dirty, you could experience a foul smell coming from the RV’s shower and sink drains. The stench is almost similar to that of a hair salon, and you should act fast before it deteriorates.

What To Do if Your RV Gray Tank Is Dirty

If the foul smell in your RV is due to a dirty gray tank, you should do the following:

  • Empty the tank. It is essential to empty the tank immediately in a designated dumping place. 
  • Clean the gray tank. Use clean water, a cleaning wand, and an all-purpose detergent to clean the tank. 

The Fridge’s Coolant Is Leaking

Sometimes, you may experience an ammonia-like smell around the RV’s fridge, because most fridges have ammonia-based coolants. If you look closely, you might notice that the fridge’s temperature has risen, and the coolant is leaking. If that is the case, act fast because breathing ammonia is harmful.

What To Do if Your RV Fridge Coolant Is Leaking

When you discover that the RV’s fridge coolant is leaking and thus producing the ammonia-like smell, you should do the following:

  • Switch off the power to the fridge. The refrigerator stops working when you switch off the power, so the coolant stops leaking.
  • Ventilate the RV. After switching off the power to the fridge, open the RV’s doors and windows to remove the harmful ammonia smell. 
  • Call a technician. A leaking fridge is a big deal, and calling a technician is essential. The technician can either repair the fridge or advise you to buy a new one. 

There Might Be a Fault in the Electrical System

Once in a while, you may experience the smell of burning plastic in your RV. This is due to a fault in the electrical system, which is a sign of heating up of wires or coils. The smell of burning plastic could cause untold damage to RV equipment and endanger your life.

What To Do if the RV’s Electrical System Is Faulty

If you find out that there is a fault in the RV’s electrical system that is causing the bad, burning plastic smell, you should do the following:

  • Switch off the power in the RV. Before you start exploring the fault with your RV’s electrical system, switch off the power to keep yourself safe. 
  • Call an electrician. It’s always good to call an electrician to handle electrical issues. 

Your RV Might Have Mold

You might experience a musty, cave-like smell in your RV. Since RVs are compact, there is inadequate ventilation, and they, therefore, hold onto moisture. Mold thrives in such places, and the cause of the musty smell is usually mold growing in the RV due to humidity.

How To Deal With Mold in the RV

If you suspect that your RV smells terrible due to mold, here is what to do:

  • Look for signs of mold. The best places to check for mold in your RV include the floor, ceiling, walls, closets, or cabinets. 
  • Treat the mold. Once you pinpoint the locations of the mold, treat it with bleach. If the mold in the RV overwhelms you, look for professional help.

For a full rundown of the various kinds of mold that grows in RVs and how to remove it, read our helpful guide to Mold in RV Walls here.

There Might Be Pests and Stink Bugs

Some pests like rodents and stink bugs could be why your RV smells terrible. Rodents smell horrible and a nest with rodents’ droppings also smells awful. In addition, if your RV has stink bugs, they can make it stink, as they produce a horrible smell like that of burnt tires. 

What To Do About Pests and Stink Bugs in the RV

If your RV smells terrible due to an infestation of stink bugs and rodents, get rid of them before they increase. For instance, you can use a natural repellant such as neem oil to get rid of stink bugs. Or you can implement several cleaning routines to keep them out of your RV. For a full guide on bug removal, check out our post, Tiny Bugs in a Camper and How to Remove Them.

How To Keep Your RV Smelling Fresh

As mentioned earlier, many things can make your RV smell bad. Here is how to keep your RV smelling clean and fresh:

  • Keep the RV clean. To keep your RV fresh, keep it always clean by cleaning the drainage, tanks, dishes, and floors.  
  • Use a dehumidifier. Using a dehumidifier reduces the amount of moisture inside your RV. So, the buildup of mold and mildew in the RV will decrease, leading to a fresher smell. 
  • Air out the RV. It is best to air out the RV whenever the weather is good. Open the doors and windows to remove the foul smell. 
  • Minimize the use of the RV toilet. When you use the RV toilet too often, the black tank is likely to fill quickly and start smelling. If the campground has restrooms, use them whenever possible. Or, when on the road, use gas station restrooms whenever possible.


Funky smells are bound to come up while living or travelling in a small space like an RV.

Luckily, most offensive scents are easily fixed. First, find the reason for the smell: Check the trash, the black tank, inspect for mold, and any the other common problems. Once identified, a little DIY cleaning can typically remove the bad odor and you can enjoy your RV, odor-free, once again. 

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