How to Backwash an RV Tank

How to Backwash an RV Tank
Backwashing your recreational vehicle's holding tanks is not the most pleasant part of RV ownership. It is important to backwash the holding tanks on a regular basis, though. This will remove solids and prevent a buildup of material that can lead to trouble down the road. It is a good idea to get into the practice of backwashing the holding tanks whenever you empty them. An additional benefit to regularly backwashing RV holding tanks is a reduction in noxious odors from the black water tank.


Difficulty: Easy

Things You’ll Need:
  • Tank flush fitting with a clear plastic elbow so you can see the water's color
  • Garden hose
  • Sewage hose
  • Water softener
  • 1-gallon bucket
Step 1
Put the end of the sewage hose into the dump station opening.
Step 2
Make sure the outlet valves for both the gray and black water holding tanks are closed.
Step 3
Remove the drain pipe cap and connect the sewage hose to the flush fitting and the flush fitting to the drain pipe.
Step 4
Attach the garden hose to the flush fitting.
Step 5
Open the black tank outlet valve and the flush fitting valve. Let the tank empty.
Step 6
Close the flush fitting valve.
Step 7
Turn on the water for the garden hose to fill the tank.
Step 8
Turn off the water to the garden hose when the tank is full.
Step 9
Open the flush fitting valve to empty the tank.
Step 10
Close the flush fitting valve when the tank is empty.
Step 11
Dissolve 2 cups of water softener in 1 gallon of hot water. Flush this down the toilet.
Step 12
Turn on the water to the garden hose to fill the tank.
Step 13
Turn off the garden hose and open the flush fitting valve to empty the tank.
Step 14
Close the black water tank valve.
Step 15
Open the gray water tank valve and repeat these steps to backwash this holding tank.

Tips & Warnings

Backwash RV holding tanks working from dirty to clean. This will keep your sewage hose and the RV piping system clean.
Never dump gray or black water on the ground.

Article Written By Mark Quest

Mark Quest began his writing career in 2009, contributing to various online publications. He attended Asheville Buncombe Technical Community College, focusing on the sciences.

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