Written by 1:26 am Common Questions

Camper Smells Like Sewage (How To Fix It)

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Many people like to camp with RVs or campers. RVs provide a great way to enjoy the outdoors while also having some of the amenities of home.

However, your relaxing vacation will come to a screeching crash when you walk in to find a stench unlike any other and your camper smells like sewage or rotten eggs.

When that sewer stench comes, you may feel like it’s the end of the world. How can you possibly enjoy camping with that smell hanging around?

The good news is most of the fixes for this smell are fairly simple.

In just a short time, you could be back to breathing deeply; you might not even have to spend a dime on expensive cleaners or fixers but use the materials you already have available.

How do RV Toilet Systems work?

RVs have three holding tanks. One for fresh water for drinking and showering, one for gray water or water that has come from showering or washing dishes, and black water for waste.

The gray water also helps to keep the waste thoroughly mixed with liquid so it doesn’t dry out. When the sewer line is closed, the liquid stays in the tank and keep the solid waste wet and decomposing.

However, if the line remains open, the fluids leave and the waste dries out. It becomes much harder to clean the tank and to keep it running well.

The reason RV toilets need water from the gray water tank is that they do not use a lot of water in their flush.

Unlike toilets in a home, RV toilets are more like airplane toilets. They require only gravity and a small amount of water to be flushed.

In some RVs, the toilet will have a spray nozzle nearby to rinse down any extra waste. It is possible to fill the tank with water and flush if more water is needed to flush away the black water.

Because of this, it is important not to flush certain things down an RV toilet. Flushing these things could create a clog or a lack of decomposition in the black water tank, leading to sewer smells.

Do not flush paper towels, feminine products, or toilet paper not specifically specified for septic tanks.

Why Does My Camper Smell Bad?

There could be several reasons why your RV has begun to stink. Several of these can be fixed right away by yourself, though some problems should be handled by a professional.

  • Clog– A clog is one of the easiest of the fixable problems. When a drain is clogged, the material stuck inside will begin to decay and produce that sewer smell
  • Dirty Toilet and Flapper– If the toilet is not regularly cleaned, toilet paper and waste can get under the rim and on the underside of the drop seat. It begins to decompose and cause smelly odors.
  • A Slipped or Broken Wax Ring– When the sealing ring that connects the toilet tank to the black water tank slips or breaks, it can cause space for aromas to leak out.
  • The Black or Gray Tank has not been Flushed– Waste builds up inside the tanks. If the valves are left open, the smell drifts back into the camper. When the waste dries out, it can also cause stink problems. Making sure your tanks are emptied and clean is the number one way to remove any sewer smells. It is important to note here that the gray water tank can stink just as bad as the black water tank.
  • Sink Drain Vent Issue– whether the sink drain uses a one-way vent or a sewer vent pipe that runs up to the roof, you could have a problem with it being stuck, broken, or blocked. If you are knowledgeable in cleaning or replacing pipes, this is a fix you can manage. However, a professional will probably be your best bet.

How to Get Rid of the Smell

1. Unclogging your RV toilet

There are several options to unclog your toilet. Below are three options for you.

  • Open toilet valve and pour several pots of hot water down the toilet. Let the water sit overnight in the tank and soak. Driving around can help mix it all in, allowing the clog to loosen and flush through.
  • Another method is to use ice by putting ice into a full toilet of water. Be sure to only fill the water part way before adding the ice and then add the rest of the water. Flush the toilet and drive around to allow the ice to push the clog through. After a few flushes, the clog should be cleared.
  • Your last option is de-clogging chemicals. There are many different types and any meant for RV toilets will work. If you have been using household toilet tissue, Thetford tissue digester eats tissue clogs in your tank and within your line.

2. Unclogging RV Shower Drain

  • First check to see if the gray water tank is full. It the tank is full, try emptying it, it may be possible that the “clog” was just water with nowhere to go.
  • Plunge shower with sitting water in it with a sink plunger. If water does not drain after several attempts, try one of the following methods.
  • Pour an enzyme-based drain opener designed for RV use down the drain. Let it sit in the drain overnight to allow time to dissolve the clog. Run hot water down the drain the next morning. Plunge the shower drain if clog still remains.
  • Instead of buying a chemical drain opener, make your own drain opener using 1 cup of baking soda and 1 cup of white vinegar. Follow the directions above for the drain opener.
  • Look down the drain with a flashlight to see if you can identify the offending clog. If you can see an object or hairball causing the clog, try to remove it with a coat hanger wire

3. Unclogging RV Sink

  • Check gray water tank, just like with unclogging a shower drain.
  • The first place to check is the kitchen downpipe. Place a catch pan under the p-trap under the sink and remove the p-trap. If the water drains, there is no clog in this section. If it doesn’t, use tweezers or a sturdy wire to clear out the drain.
  • Check the p-trap for standing water. If there is, snake the drain or use chemicals to clear out the clog.
  • Check the drain from the end of the p-trap to the gray water tank for standing water. If there is, you can also snake this drain or use chemicals to clear out the clog.

Warning: Do not use CO2 capsules, high-pressure air, or high-pressure water through the system. You could rupture the joints or pipes if you do.

4. Replacing A Broken Wax Ring on your RV Toilet

  • Unhook the water to the tank
  • Flush toilet to remove all the water that you can
  • Dry out the tank
  • -remove black water tank to ensure safety of your tools if they fall down the toilet-
  • Remove bolts holding toilet and remove toilet
  • Take out the old wax ring
  • Wipe down and clean area around ring
  • Replace wax ring using a plumber’s sealant
  • Re-bolt toilet down and connect water back to tank

5. Cleaning Flapper and Toilet

With a wet rag, wipe down the whole toilet from top to bottom, paying special attention to the rim and the top and bottom of the drop seat as waste and toilet paper can get stuck there and decompose. This can create a sewer smell.

6. Emptying Black Water and Gray Water Tanks

  • Before dumping, make sure you have the proper tools including hoses, disposable gloves, sewer adapter, etc.
  • Make sure you are as close to the dump station as you can be.
  • Dump your black water tank first
  • Attach your hose to the dump station before attaching it to the black water tank to avoid any accidental spillage
  • Open Black Water Tank and empty it.
  • Fill the toilet with water and flush to rinse out the black water tank or if you have a black water rinse tank built in, use that to rinse the tank. Do not use a fresh water hose for this task.
  • Open Gray water tank and empty it

You may be interested in this post I wrote here about if its okay to empty your RV tank into your home septic tank.

7. Flushing and Cleaning Tanks

  • Fill the tanks ⅔ to ¾ with water. This gives the cleaners a chance to reach all parts of the tank.
  • For your gray water tank, use ½ cup of OxiClean with 2 cups of hot water into the partially filled closed tank. Driving with this after dumping will give it time to swish around and clean the inside of the tank.
  • For your black water tank, add two cups of liquid bleach. Let sit for 10 minutes before draining. Fill ¾ with fresh water and drain. Repeat this until no solid debris comes through the hose. If you prefer not to use bleach, you can also use laundry soap and a bottle of pine sol. Let sit for an hour and then drain.
  • Always fill both tanks at least ⅔ full with fresh water after you flush.


It is important to add an enzyme treatment to your black water tank to help waste decompose.

Any treatment meant for RV or camper toilets will work, like Pure Power Holding Tank treatment from OP products, Rid-X, and Camco’s TST RV toilet treatment are all good options. My recommendation though is Porta Pak which can be found here on Amazon.

Make sure the enzyme treatment is poured/dropped into a partially filled tank.

Tips to Prevent Smell

It is important not to empty your black water tank too often. When it is emptied before it is full, solid waste is left. The waste will get caked to the sides and won’t decompose properly as well as interfere with the tank’s sensors.

Keeping dump valves closed even when hooked up to sewage systems is a good idea as well.

When these valves are open, the smell can seep back into the camper or into the vents to permeate the whole vehicle.

Only open the valves when dumping or flushing.

Taking care of your holding tanks is important not only for your nose but to maintain a working sewage system. When tanks fall into disrepair or are not cleaned on a regular basis, waste builds up and can even corrode tanks, pipes, or hoses.

If you empty your tank when it is full and give it a good flush every time, you should only need a deep cleaning every couple months, depending on how often you use your RV or camper. Good luck with going smell free!

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