Sunday, March 26, 2023


Dump your holding tanks from inside your RV

By Chuck Woodbury

What modification have you made to your RV that has had the most positive impact on your RV lifestyle? That thought came to me in the shower this morning. Here’s why.

As I enjoyed the initial pleasure of the warm water, I noticed the drain was backing up — a full gray water tank! I routinely keep the gray water tank closed until it’s full or almost full, as we all should do.

For most RVers in my situation, dumping the tank would mean drying off, dressing and going outside to pull the cable valve — or convincing your partner to do the same. In bad weather this chore is no fun (you know that, don’t you?).

But, for me, I simply stepped out of the shower, took a step and flipped a switch on the wall. The tank began to empty as I returned to my shower. So easy! I bet you can’t do that!

To dump my tanks, I push the switches on the wall, one for the gray tank, the other for the black tank. There is no need to go outside to perform the chore.

A company called Drain Master, of Hollister, Calif., installed the electronic valve system three years ago (it’s a fairly easy do-it-yourself project, too). I have never had to step outside to dump my tanks since then, although I could if I wished to (there’s another switch in the sewer control bay). I will never own another RV without this system. And I mean never!

It includes a super-sturdy, permanently-affixed Waste Master hose, which has a cam-loc fitting instead of the typical bayonet fitting used by the RV industry (other industries do not use this cheap, unreliable system). The nozzle at the end of the hose can be shut off at the sewer inlet to further ensure no messy spills. I imagine the hose will last as long as most RVers own their RV (and probably long after).

The system’s inventor, Doug Swarts of Drain Master, has installed the same system as mine in hundreds of other RVs. But despite it being one of the most useful accessories any RVer could ever have, it has not gained wide popularity.

The Waste Master hose, itself, without the electronic dumping feature that I have, is more widely used but dwarfed in sales by cheap hoses that break or spring leaks every year or two. High-end RV manufacturers Foretravel and Newell include the hose and “push button” dump feature as standard equipment in their coaches. But other coach makers, for whatever reasons, do not.

The sturdy Waste Master hose

Once you own the system, you will wonder why any avid RVer would not pay a little extra for this incredibly useful tool. I mean, how many times in the pounding rain or freezing cold have you cursed that a holding tank was full and you needed to go outside to dump? I never need to do that!

If you want to learn more about the hoses or the system like mine, you’ll find several videos here or you can call 877-787-8833 or visit I’m sure Doug would be happy to answer your questions.

This article originally appeared as the opening essay in issue 933 of the newsletter.



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Gene Bjerke
10 months ago

I have occasionally thought about putting the same sort of remote valve on the propane tank, similar to systems on a sailboat. This would allow me to turn on the propane when boondocking without having to go out in the rain.

10 months ago

Macerator is the answer for me. I actually have a spare portable one in the RV. Would be easy to remote the switch to anywhere in the coach. Never saw the need.

Phil & Peggy
1 year ago

IMHO most of the commenters below entirely missed the point of the article, focusing on the hose instead of the remotely operated dump valves. I had my valves installed last April, after doing it the outside manual way for 20 years, and I wouldn’t go back to the outside manual way for love nor money. Just since April there have been many times it was cold and/or raining, or just inconvenient, when I needed to dump and it was worth every penny to be able to just push a button. Of course the hose was already deployed, but the point of the article was the remote operation of the valves. Even with the hose deployed, you DO keep both valves closed until you need to dump, don’t you?

Dave J
2 years ago

Electronic dump, eh? Would that be useful if rolling down the highway and being harrassed by some bikers behind ya? Naw, probably not. The cap would be on the outlet…….grin.

Crystal Limerick
2 years ago

I have the Waste Master system and love it. No hose leaks, even at the fittings. Great purchase.

2 years ago

There have been times when I wished I had such a button to push, but on the dashboard not in the bathroom. Then I’d want to route the black hose to the rear of the RV. Voila! The Tailgater 3000!

jane shure
2 years ago
Reply to  Dan

Has the problem of the valves sticking been solved.

David Hagen
2 years ago

But you still have to go outside and hook up to the sewer drain. Also, I only close the grey water valve when parked for a while the day before I dump the black tank.

Doug Swarts
2 years ago
Reply to  David Hagen

The sewer drain hose is always connected to the RV and inserted in the ground sewer inlet when you first arrive during the hook up process. Leaving your Gray valve open all the time upsets the park venting balance and may/could cause sewer gas smells in the park. In addition, this is an open invite for things like sewer rodents and flies to enter your RV. A lot more than you may think!

2 years ago

I feel like that will make it to easy for people to dump on the side of the road. It should not be able to dump without the hose attached

Doug Swarts
2 years ago
Reply to  Danpa

In this case, the hose is always attached to the RV and has a shut off built into the sewer inlet nozzle.

2 years ago

Dump your tank without going outside! Fantastic, what does the hose do, magically slink it’s way to the sewer pipe and connect itself? I find this item of little practical value, if any.

Doug Swarts
2 years ago
Reply to  friz

The hose is connected to the RV at all times and has a nozzle with a shut off on the sewer inlet end. The hose is simply extended from the RV and the nozzle inserted in the ground sewer inlet. Then you open the shut-off built into the nozzle and leave it for your stay. The value is the convenience as well as it is the most sanitary and environmentally friendly method of dumping your waste without compromise.

T. Saroch
2 years ago
Reply to  friz

I totally agree about it being of little value. I bet it’s not cheap either & in the photos it appears rather large & bulky. If you don’t know when to dump your tanks while being parked perhaps these folks should perhaps stay in a motel. The biggest hassle is getting the hose out & putting it in the sewer drain, the rest is childs play .

Brad Teubner
2 years ago

I never leave the hose out. No big deal to connect and dump once a week or so.

Dennis K
2 years ago

You still have to go outside to rinse the black tank, lay out the hose and pick it up when leaving. It seems to me to be an expensive convenience for a very occasional problem. But to each his own.

2 years ago

Like Bob P below, I keep track of when I dump and how many showers we take. I dump at 2/3 full, and usually the gray can fill and dump twice for every fill and dump of black. 2 gray tanks, 2 black. This rig has the mascerator pump and 1.5” hose, it’s much easier to use than the 3” slinky hose, I keep a new one of those as another option in case the mascerator has a problem. There is a connection for that as well.

Bob P
2 years ago

I just schedule a time to go outside and drain both tanks after so many days, done at my convenience usually early in the morning before the heat of the day.

Dan Fabian
1 year ago
Reply to  Bob P

I 100% agree with you.

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