How To Use Black Tank Flush System?

Cleaning out the infamous Black Tank is undoubtedly the least attractive of all the tasks facing RV owners. But we RVers can’t afford to be squeamish. Your RV Black Tank System must be flushed properly if you want the vehicle’s toilet to operate hygienically and comfortably.

Learning how to use a Black Tank Flush System and adhering to routine maintenance procedures will ensure sewerage problems don’t spoil your RV trips. Let’s don our rubber gloves and plumb the depths!

To effectively use an RV Black Tank System, connect the sewer hose to the RV Flush Port and the Dump Station. Open the RV Waste Valve and drain the contents of the tank. Close the Waste Valve and refill the Black Tank with clean water. Open the Waste Valve and flush the tank again.

As with any RV system, knowing how an RV sewerage system operates is crucial to its optimal functioning. It’s quite elementary, and with an understanding of the various RV Toilet, Black Tank, and Sewer Hose operational and maintenance requirements, Black Tank cleaning duties will be a breeze. Read on to discover the necessary steps to hassle-free flushing and happy RV travels.   

What Components Constitute A Black Tank Flush System?

When setting out to become a proficient Black Tank flusher, it’s vital to know what components comprise your RV’s sewerage system. The best way to begin is to focus on that magical liquid – WATER – and follow its path to the Dump Station.

Your RV toilet is the epicenter of the vehicle’s sewerage system, and Water is its lifeblood.

  1. The toilet is fed water from the freshwater tank.
  • Water passes through the toilet ball valve when the toilet is flushed.
  • Toilet water (with or without pee, poop, and toilet paper) then feeds directly into the Black Tank.
  • The Black Tank has an outlet that connects to the RV Waste Port.
  • The Waste Port has a valve and a valve handle.
  • A Sewer Hose connects to the Waste Port on one end, while the other connects to a Dump Station hookup.
  • A water hose connected to a Dump Station spigot feeds the RV’s Black Tank Flush inlet port.

RV Black Tank Flush Systems vary in the way they’re configured, but the above components all play a part in the success of a Black Tank flushing operation.

How Do I Maintain My RV Black Tank Flush System?

Bearing in mind that the sewerage system components mentioned above all contribute to keeping your toilet and Black Tank healthy, each needs to be maintained regularly to ensure trouble-free operation.

  • Once again, it’s all about Water. More specifically, maintaining optimum Water Levels and Water Treatment.

Follow these guidelines:

  1. Your RV toilet should have three inches of Water in it when not being flushed. Water in the toilet bowl will dilute solids and liquids and create a seal around the toilet’s ball valve to prevent odors from rising from the Black Tank into the RV.
  • Fill your Black Tank with water to 65-75% of its capacity to dilute and break up waste.
  • A bio-friendly water treatment product should be added to the Black Tank to sanitize and deodorize the tank.
  • Your Sewer Hose must be properly sanitized and stored in an airtight container when not in use.

With these routine maintenance procedures strictly adhered to, your Black Tank flushing operation will flow smoothly.

When Do I Flush My RV’s Black Tank?

How often you flush your RV’s Black Tank will depend on how many people use the toilet and how often they use it. The industry standard is:

  • For a family of six, flush every other day.
  • For a couple, flush every five days.

How Do I Flush My RV’s Black Tank?

When the flush day arrives, make sure you have the following items to make your stop at the Dump Station as effective, swift, and safe as possible:

  • Rubber gloves.
  • A good-quality Sewer Hose with an Inspection Elbow that allows you to monitor the cleanliness of the water being drained from the Black Tank.
  • A garden hose to flush the Black Tank with clean water.

A Black Tank flushes more efficiently when it’s full. Inspect the tank’s water level via the toilet valve and flush the toilet until the Black Tank is full (or fill the tank using the inlet hose or a bucket).

Follow these steps:

  1. Attach the Sewer Hose to the Waste Valve connector.
  • Attach the other end of the Sewer Hose to the Dump Station junction.
  • Open the Waste Valve by pulling the handle.
  • Attach the clean water hose to the RV and external Dump Station spigot. Allow it to run while the Waste Valve is open and flushing out the Black Tank.
  • When the water is 100% free of debris and clear, turn off the spigot and close the Waste Valve.
  • Fill the Black Tank with clean water. Make sure the tank is at least 65% full.

Your Black Tank should now be free of 99.9% of the waste material. But you can go further if perfection is your thing.

Killer Black Tank Flush Tips

  • Add several bags of ice cubes to the flushed tank via the toilet before refilling it with water. Now go for a romp out on the road in your RV and bounce those ice cubes around. They will dislodge solid waste stuck to the bottom and sides of the tank.
  • Empty your Grey Water Tank using your Sewer Hose. The soap in the Grey Water will clean the Sewer Hose.

Your #1 Black Tank Flush System Must-Have:

  • A clear plastic Sewer Pipe Elbow


With solid routine maintenance and the right headspace, your Black Tank will become a faithful comrade on your travels rather than a monster you’d rather not think about. Follow these guidelines, and your Black Tank Flush System will purge pure and simple, and your water closet will become another luxurious chamber from which to imagine your next exciting adventure!

Good luck, and happy camping!

Check out our article one: Best RV Black Tank Cleaner

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