Eliminate the foul odor in the freshwater system after your RV comes out of its long winter’s nap
Every year around springtime, we start to hear from readers who have discovered their RV’s freshwater system has developed a foul odor and want to know how to cure the problem. In truth, prevention is the best medicine; the system should be thoroughly drained before it is stored for the winter, and in cold climates, winterized as well. That being said, a lot of inexperienced RV owners will have a stinky freshwater system and want to know what to do about it before heading out on that first trip of the season.
The most common approach for treatment is to use a small amount of bleach, pumping it through the system and allowing it to sit, followed by another tank with baking soda to remove the chlorine smell. (For a how-to video of this method, visit our YouTube channel, TrailerLifeDIY.) It works, but it’s not a hard science. How much bleach and baking soda you use depends on the size of the tank and the severity of the problem.
Thetford offers a Fresh Water Tank Sanitizer system that takes the guesswork out of the process, and it’s effective as well. Not only does it remove odor, but it kills harmful bacteria that may be present, including Staphylococcus aureus and listeria. Both bottles in the two-part system provide clear instructions on how to use the products, but what may not be as clear is how to actually do the job.
After adding the cleaning solution, fill the freshwater tank and run the diluted detergent solution through each faucet, shower and any other water outlet (including the exterior shower, if equipped) for approximately one minute.
Go back to the low-point drain and empty the freshwater tank. Then, close it and refill the tank with water and repeat the process, flushing the solution out of all water outlets.
Finally, add the contents of the Tank Sanitizer bottle at a ratio of 2 ounces per 8 gallons of water. Flush it through the freshwater system and drain the tank. You can now refill the tank and enjoy clean, odor-free water.
For this, we turned to C&S RV Service Center in Oxnard, California, and followed along as one of the technicians sanitized the water system on a customer’s fifth-wheel. The whole process takes only an hour or so (depending on the size of the freshwater tank), but be advised that you will be using a lot of water — so make sure drainage will not be an issue where you decide to perform the job.
For those who have concerns about dumping a chemical down the storm drain, the good news is that these products are EPA-registered in all 50 states and are not harmful to the environment. They contain chemicals similar to those used by restaurants and hospitals to sanitize drinking glasses.
With the right product and the right techniques, an RV’s freshwater system will be as good as new again.