How To Completely Clean Your RV’s Black Water Holding Tank

by | Mar 5, 2021 | RV Owner's Guide | 0 comments

Just like cleaning everything else in your RV, cleaning your water tanks are no exception. It’s crucial in keeping a clean and hygienic sewer system, and cleaning it regularly will keep your RV in top shape in case you decide to sell it later on. In this blog, we’ll go over how to clean your black water tank, the one that holds the toilet waste. It’s not the most glamourous or fun task, but it prevents unwelcoming odors from seeping into the interior of the rig. It also keeps your tank sensors working correctly.

Keep reading to learn how to properly clean and maintain your RV’s black tank!

Before you start… it’s a good idea to buy and designate a hose specifically for cleaning the black water tank so no cross-contamination occurs. Try to dump when your tank is about 75% full, and always wear gloves to protect yourself from splatters or drips!

First, you’ll want to close the gray tank valve the night before you start cleaning. You can keep it open when you’re hooked up, but it’s a good idea to gather some water to rinse the sewer line out after you’ve dumped the black water. Try to leave the gray water tank closed overnight to collect around half a tank of water.

  1. Time to clean the toilet. Knock this out now so it’ll be clean for your next trip. You’ll want to turn the fan off before you start, and hopefully, you have it turned off each time you flush your toilet! It’s also a good idea to open the gate valve, grab a brush, and clean that out really well. After you’ve scrubbed, flush a few more times to ensure cleanliness.
  2. Connect the hose. Remember the hose you bought specifically for this task? Time to hook it up to the anti-backflush valve. Attach it to the sewage rinse on your RV, and the other end will attach it to your freshwater source.
  3. Turn the water on. Be careful with this step; don’t turn it on too quickly or you might end up with a mess. Pull the black water tank valve, then turn the water on more until the water runs clear. You’ll do this step a few times until the black water tank is full. Don’t leave it unattended, because you don’t want the tank to overflow and pour out of the vent on top of your RV.
  4. Repeat these steps. If the water is running mostly clear, it’s not necessary. But, repeat these steps as many times as necessary until the water does run mostly clear.
  5. Turn the water off. Allow the remaining water to drain, then close your valve. Open the gray water tank again, and let that water drain.
  6. Head back to your RV’s bathroom. Pour a small amount of cleaner followed by a gallon of water down the toilet.
  7. To run a test, close all windows and open the toilet’s gate valve. When you turn the bathroom fan on, there shouldn’t be any odor you notice coming from the black water tank. If you do, no problem! Simply keep pouring small amounts of cleaner down followed by a gallon of water. Or, you can pour ice down the toilet. As you let the ice settle and melt, it will help knock debris and dirt off the bottom of the tank. Be sure to dump one more time to rinse out the collected dirt.
  8. If this doesn’t work, there’s one more thing to try. Pour a larger amount of cleaner down the toilet (about a cup) followed by one gallon of hot water. Let this sit for at least 24 hours, drain and try the test again.

We know it isn’t a glamourous job, but you’ll feel much better when you knock it out and get it out of the way. Be sure you’re fully hooked up and have both water and sewer connections before you start. It makes it easier but can be done without both if needed. Also try to avoid using any harsh chemicals or antifreeze for this deep clean as it may ruin or rot rubber seals, ultimately ruining your sewage system. Remember to try to deep clean after each trip, because you probably don’t want your RV sitting with wastewater in the tanks. Any other time, it’s recommended to clean each month if you aren’t using it. If you have any questions, you can always call us or a trusted dealer in your area!

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