Why Does My RV Smell Like Sewage When I’m Driving?

Published Categorized as RVs

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Sometimes while you are traveling between campsites or destinations you may notice that an odor of raw sewage may begin to permeate your living spaces within your motorhome or RV. This is not an unusual occurrence because you are moving down the road and your black water tank may have raw sewage that is in motion and some safeguards installed by the manufacturer to prevent this from happening may not be working properly or you have overlooked some basic steps that prevent this from happening.

Photo credit: Drainmaster.com

The first step to eliminating odors emanating from your black or gray water system is to gain a basic knowledge of how to keep natural gases from your black and gray water tanks from escaping back through the pipes that are designed to drain the waste into the tank. For this, most systems are equipped with a p-trap that is designed to hold water in the line and prevent gases from escaping from your drain lines.

A good way to prevent this is to dump a cup or two of water down the drains before you hit the road and to always make sure any p-trap in your rig has water in its trap.

Photo credit: RV Doctor.com

These days, more and more manufacturers are installing new devices such as the HepvO valve which eliminate the need for a p-trap and the need to hold water to work effectively.

The HepvO valve is designed to be flexible as well as self-sealing. An internal silicone membrane will open when water flows through it once the flow is shut off it will close and prevent odors from escaping up the line.

The HepvO valves are very innovative and I would recommend anyone that is restoring or designing a system for an RV or van build consider using them. Not only are they more reliable than a p-trap as far as water usage is concerned, but they will save you space under cabinets as well as being more protected in the undercarriage of your RV.

Another thing to consider when you have unwanted odors from your waste tanks is whether they are vented properly. As a rule, RVs will have a roof vent that allows gases to escape through your roof just as you would find in a traditional home. This will often fail over time due to weather, age or in some cases bird or insect infestation.

Just as manufacturers have designed more innovative ways to deal with these problems by developing things such as the HepvO valve, they have also been designing ways to vent the sewage gases.

One item I highly recommend is the Cyclone Plumbing Vent by Camco Inc. and sold at many major retailers.

Camco 40595 Cyclone Sewer Vent Cover, White
  • Use the power of the wind to draw holding tank odors out of the RV
  • Rotates 360 degrees to follow the wind
  • Attaches easily to any RV plumbing vent

Last update on 2024-02-14 / Affiliate links / Images from Amazon Product Advertising API

Once installed on the roof of your RV, these vents are designed to use aerodynamic to create a vortex that will successfully draw the air away from your holding tank while you are traveling.

If these options don’t work for you and you are still experiencing strong odors, then you may have to consider replacing your toilet seals or even your toilet. This option is rare so I would suggest taking the steps that I recommend here before you take these measures.

As always friends, thanks for following me and reading my articles while I travel around this great land. Safe travels to you and I hope to see on the road someday.

Got more smelly issues? Don’t worry, read these guides first.

By Brian

Born and raised in Michigan, contributing writer Brian C. Noell is a retired hospitality industry professional that now works remotely as a visual artist, writer and photographer as he travels around the United States in an RV with his dog Lizzy, an eighty pound Appenzeller hound dog.