Saturday, October 23, 2021


Why didn’t I think of that?! An easy trick to keep your sewer hose clean

I had a chance to attend a seminar last week on all things black and grey tanks and learned a new dump technique. After all these years of RVing, I had never heard of or thought about this sensible tip to keep your sewer hose clean.

Here is a quick, easy tip to help keep your sewer hose clean:

When planning to dump the black tank, first pull the gray water valve for about three seconds, then close to allow the gray water to run through the sewer. The few seconds of water running through the sewer hose will wet it down and coat the inside. This helps prevent debris, particularly from the black tank, from sticking in the crevices and around curves. Thinking of all the places gunk can collect, particularly around the wires, makes this technique make a whole lot of sense. This technique also allows you to check for leaks before dumping the black tank.

Pulling the gray water valve when done further rinses out the sewer hose. Listen for that welcome whoosh of a full tank swirling around, scrubbing the insides of the tank, and fully emptying.

Did you know about this trick?


How many sewer hoses does an RVer need?

Camco RhinoFLEX 45-degree clear sewer hose swivel fitting



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Steven Peterson
3 months ago

great idea like using the gray water to flush the hose.

John Koenig
3 months ago

I read about that technique about a DECADE ago and, since then, I have posted about it on several RV sites. It made great sense when I first read about it. In addition to “lubricating” the hose’s interior, it gives an RVer a chance to check connections and integrity of the sewer hose. Should there be a problem, you’d be dealing with grey water rather than black water.

Dennis O
3 months ago
Reply to  John Koenig

Exactly John, I started doing this technique 20 years ago after my discovering a pin hole in my hose and always questioned why all through the years we were taught to open black water valve first.

Scott Hunter
3 months ago

I also do a triple rinse of the sewer hose after I have dumped.

Jeff Craig
3 months ago
Reply to  Scott Hunter

And a 10 second shot of Lysol spray (until the mist starts to spew from the other end of the hose) also kills ‘kilng-ons’ and keeps the hoses smelling good.

John Koenig
3 months ago
Reply to  Scott Hunter

Oh, so YOU’RE the guy who’s holding up the line at the communal dump station……. 😉

Ron Lane
3 months ago

I’ve gone one step further by adding a third valve installed after the black/gray valve and before the clear connector that the sewer hose is connected to. With both tanks at least 2/3rds full, I will open the 3rd valve and also open the black tank valve (with the black tank rinse running) and let it run until almost empty. I then will close both the black tank valve and the 3rd valve and open the gray tank valve. Once I hear the Y connection is full, I will open the black tank valve and allow the soapy gray tank water to flow into the black tank. Once the two tanks have equalized, I will then close the gray and open the 3rd valve allowing the black tank to drain again. Typically I will do this at least twice. To finish, I will close the black tank (while the rinse is still running) and open the gray to empty it and to clean out the sewer hose. After a few minutes I will turn off the black tank rinse and close all valves.

James Starling
3 months ago
Reply to  Ron Lane

This works to help unplug the black tank pipe of tp, ect. if ever needed.

3 months ago

I always do that to check my connections before dumping the black stuff.

Jeff Craig
3 months ago
Reply to  Alpenliter

BINGO! On one of our first RV trips years ago, I saw some poor guy have his hose disconnect from his slide-in camper when he pulled the valve handle. From that point on, I’ve always ‘splashed’ the grey tank about five seconds. (You DO NOT want to be… THAT GUY!)

Neal Davis
3 months ago

Great idea! Very logical. Will do this going forward. Thank you! Have a great weekend!

Steve Cloninger
3 months ago

There is another reason for opening the gray tank for a few seconds. If there is a hole in your sewer hose or a bad connection, you will know within, rather than with the black tank contents.

3 months ago

I installed a Camco Torpedo tank flusher on my Coachmen Class C. After I dump I turn the water on and rinse my tank and HOSE. Works good and keeps both clean.

Sink Jaxon
3 months ago
Reply to  bjensen6

Oh…you mean a Camco TORNADO tank flusher…

3 months ago

Having full tanks before dumping increases the flow rate also. I add additional water to the tanks before I dump. Good tip.

Hook n' Haul 789
3 months ago

That is the procedure I have used for years. An added benefit is the first grey water segment will disclose any leaks in the hook-up. Better to clean up grey than black spills.

3 months ago