6 Steps to Flush RV Grey and Black Tanks

Dumping the grey and black tanks on a camper isn’t a difficult process but it’s an important one that you definitely want to do right. This is a quick overview of the basic steps.

1.  Pre-Check and Hook Up

Make sure the grey and black tank valves are closed before removing the cover. Remove the cover, connect the sewer hose and place the end in the sewer pipe at the dump station or campsite.  

2.  Check All Connections

It’s so simple it’s easy to overlook but the last thing you want is to open the black tank valve and realize there’s a loose a connection somewhere. That is a mess you won’t soon forget. Make sure your sewer hose is fully connected to the discharge pipe on the camper. If you need to use more than one sewer hose to reach the sewer pipe make sure they’re firmly connected and be sure the end is fully seated in the sewer pipe. It’s also a good idea to put some weight on the end (a brick or have a second person hold it) as I’ve seen them dislodge when the flow starts.

3.  Dump the Black Tank First

While the grey water isn’t exactly clean, it’s certainly much cleaner than the black “water”. Dumping the black tank first and the grey tank last will help flush the remaining black water from your sewer hose. Pull the black tank valve and let it flow until it stops. Close the black tank valve.

4.  Dump the Grey Tank

Pull the valve and let it flow until it stops. Close the grey tank valve.

5.  Disconnect

With both tanks emptied and both valves closed, detach the sewer hose from the RV discharge pipe. Be aware that a small amount of liquid will probably leak out from the pipe. It’s just a little residual grey water and is pretty much unavoidable – again a good reason to dump the black tank first. Hold the end of the sewer hose up to allow any liquid left in the hose to travel to the end and into the sewer. With the camper end of the hose still elevated, walk towards the sewer pipe end to encourage any remaining water to empty out of the hose.

6.  Clean up

If you’re at a dump station there is probably a non-potable water hose you can use to flush anything remaining in your sewer hose down into the sewer. Also, use the water to clean anything you may have spilled on the ground as a courtesy to the next camper using the dump station.

Also see”Grey and Black Tanks 101” and “8 Tips for Flushing RV Grey and Black Tanks“.