How to Flush Your Black Tank After Dumping Option 1: Built-in Black Tank Flush System

If your RV has a built-in black tank flush (check your RV manual):

1. Empty the Black Tank First
   Connect your sewer hose and dump the black tank until it's empty.
2. Connect a Water Hose to the Flush Inlet
   Never use your fresh water hose—use a separate hose clearly labeled for flushing.
3. Turn on the Water
   Let it run for 5–10 minutes. It sprays the inside of the tank to remove stuck waste.
4. Monitor and Drain Again
   You can watch through a clear sewer elbow until the water runs clear.
5. Turn Off the Water and Disconnect
   Be sure the black tank valve is open while flushing to avoid overfilling and damage.

Option 2: Manual Flush (If No Built-in System)

1. Dump Black Tank as Usual
2. Use a Tank Wand (for Toilets With Direct Access)
   Insert a tank flush wand down the toilet to spray and clean the inside of the tank. Requires some water pressure.
3. Or Use Buckets or Internal Water
   Add several gallons of clean water back into the tank and let it slosh while you drive—then dump again at the next stop.

Pro Tips

• Always flush the black tank first, then the gray tank to help rinse out the sewer hose.
• Do this every time you dump, especially on long trips or hot days.
• Occasionally add a tank treatment (enzyme or bacterial) to break down solids and control odors.