Kit to replace Drain Master 3″ 12-V DC valve (Premium Version)


Features 303 Stainless Steel Gearing made in Switzerland.


  • White magnetic switch on back
  • 2 seals
  • 4 nuts and bolts
  • 1 packet of Molykote 111 lubricant (formerly Dow Corning 111)

Wire and plug length is approximately 4 inches


Originally designed for emptying your holding tanks. This 3″ 12 volt DC Gate Valve can be installed on in a variety of applications. It opens or closes with the simple push of a button from the LED operator switch mounted at your choice of location.

Kit includes:3″ electric gate valve, set of 2 seals, Mate-N-Loc connectors on all electrical wires (wire and plug length combined approx 4″), LED Sensor (pre-mounted on back of gate as shown above), nuts, bolts, Dow 111 lubricant, 1/8″ Allen wrench (to operate manual override) and complete installation instructions.

– Push button ease
– Add a second switch to operate from a different location
– System features L.E.D. open valve indicator.
– Complete system is plug-and-play, making installation a 2-wire snap.
– Gate opens/closes in 1 second flat.

Features a double-sided manual override, including an Allen wrench attached to the valve so it is at hand when the need arises.

Technical Data

How to Use:

Full flow 3″ ABS gate valve adapts to 3″ ABS male or female bolt on specific flange fittings. Can be adapted to most pipe sizes with proper fittings and space requirements. Special seals required for sealing between valve and flanges.

A series of gears allow for a 50:1 gear reduction, developing the necessary torque.

A manual override is accessible from either side of the valve, easily accessible from the dome area.

To activate override, a 1/8” allen wrench is included. There are directional arrows for open/close. Gate is fully opened or closed with a turn and a half on the hex head.

LUBRICATION: Dow Corning 111


Installation Instructions – Pdf Files will open in new window.

General Installation Instructions

DM02-6 Drain Master Product Sheet.pdf (includes measurements)

Note: If installation is going on 1.5” piping, you need to purchase a reducer kit sold separately DM30-CR 1.5” Reducer Kit.

If you need to get Adobe Reader for opening your pdf files, click here to download. Be sure to choose PC or Mac.


The testimonials below are from our RV customers but will give you an idea of the reliability of the product.

“I live in my RV and have been using your electric waste valves for four years.  I hope to never be without them again!  Drain Master Electric Valves have changed my life.  After proper installation, my RV has never leaked.  Dumping black water is now as easy as flipping a switch from the comfort and warmth of the inside of my rig.  I would highly recommend Drain Master Electric Valves to any serious RV’ er who would like to expand their enjoyment of camping.”

Happy Camping!
Kathy S.



We have a Prowler 5th wheel. Draining the black water was a real problem, I had to crawl under the trailer to pull the drain control. Now, it’s a breeze, just push the switch and the black tank is drained. I fill the tank with a hose and drain until I see clear water flowing. We love the Drain Master.

Bob and Joan G.



I would not live without a Drain Master since on my last RV, it was a wonderful thing. I live in a travel trailer now too and have one, and it is just the best invention. I tell everyone about it…..

Debbie H.
Sierra Vista, Arizona



We love our Drain Master valves. They make emptying the tanks quick and easy.

Preston & Bev J.



We are really happy with our Drain Master valves. They make dumping much easier.

Ken & Nola S.


I have an Eagle and it takes 3 valves. They work really, really well. I am so pleased.

Joe & Barb M.

The Drain Master is a great mod to our 97′ Sea Breeze. It’s really convenient to just activate the switch and dump. I’ve coupled it with one of those piccolo pipe units that spray water in the tank while we dump. A couple of activations and we run clean and are finished! As I told National RV, the Drain Master would be a great addition to their RV’s.


Warren Y.
Cupertino, CA

I’ve got 2 of them – wouldn’t have anything else.

O J.

This is an unsolicited testimonial letter, to thank you for the outstanding service you provided on our RV during our visit to your plant last week.

We were having trouble with the electric dump valve on the black waste tank of our 2005 Phoenix Cruiser.  The key Phoenix executives felt our problem would be best diagnosed and solved by you and your staff – if we were “up” for the 150-mile round trip to Hollister and return to our home on the San Francisco Peninsula.

The purpose of this letter is to tell you-and any interested party-that the trip was well worthwhile.  You not only took care of the mechanical problem, you also provided snacks to tide us over until we could find a spot for lunch.

We arrived at your plant just before noon.  In no more than 10 minutes you and one of your factory mechanics were –literally- on the ground, analyzing our problem.  The two of you worked straight through the lunch hour, until you had replaced both the black and gray valves with your improved version of that part.  It was an important replacement for us because of the improved design of you manual over-ride feature.

You not only replaced both valves which you had manufactured-you also reinstalled a section of the waste line itself, because you noticed it was improperly aligned.

Needless to say, we very much appreciate the way you stand behind your product, and want to thank you for the courtesy and efficiency demonstrated during our visit.  We took off on a 5-day trip to the gold country the very next day and everything worked perfectly.

Thanks again.

Sincerely yours,
Les K – San Mateo, CA

This Drain Master is fabulous! No more leaning down to pull a handle that is hard to move and sometimes breaks in the half open position, making the black waste tank useless. No more repairs on the handle and no more messy hookups.

John G.
Mountain Home, ID

“The greatest thing since sliced bread! No more getting on your knees to open those waste valves, simply push the button and its done. Your trips to the dump station are clean and simple with Drain Master!!”

Nick, All Seasons RV

“Since putting Drain Master in stock, we’ve experienced great response. We chose Drain Master over other brands because we felt that their design was far superior to the other brands. Also, the service we’ve received has been outstanding!!”

Brett, Parts Manager
Michael Hohl RV,


“Drain Master will enable me to operate the holding tanks so easily, without bending, kneeling and strain. A bad back and knees made opening and closing the valve very difficult. My toughest job is now my easiest.
Thank you for the great product.

P.S. Your new sewer hose is the best ever!”


Let us know what you think about Drain Master


Can I install Drain Master on my particular RV
Drain Master will fit easily on most RV’s. It takes up only a little more space than a manual valve due to the motor. Manual valve dimensions: W 9 5/8″ x H 4 1/2″ x D 3/4″. Drain Master dimensions: W 10″ x H 6″ x D 1 3/4″. You will need additional space if you are installing on 1 1/2″ piping as you will need the separate reducer kit.
Can the switch be placed outside the RV
The operator switch (Pt 5528) is weatherproof, but it is not water-proof, therefore, it should not be installed on an exterior wall. Placing the switch in a compartment protects it from the elements as well as grandchildren’s swift and nimble hands (yes, OMG).
How do I know my Drain Master is installed correctly
As long is the valve is installed with the motor in an upright vertical position, you will install it correctly. We also have excellent Drain Master installation instructions that will walk you through the installation step-by-step. You can also call us toll free 877-787-8833 with any questions you may have during installation.
I'm getting ready to install my valve and notice that there are gaps of space when the gate is closed. Won't this cause it to leak?
The gap at the bottom and top of the gate is part of the design. The sealing against the gate takes place on the gate surface where the round lip seals are on the gate when it is closed. The gap at the top and bottom were necessary to achieve the interchangeability of existing industry standard 3” manual gate valves, which also have a gap top and bottom. The graphite impregnated rubber seals on both sides of the gate make the valve bi-directional giving it more installation options.
How do I know if the valve is open or closed?
Simply push the valve switch to the close position to ensure the valve is closed. If you purchase the LED operator switch, the red indicator light will tell you anytime the valve is open. The RED light will go out when the valve is completely closed.
How does Drain Master differ from the other Electric waste valves?
Drain Master is an electric waste valve; the others are attachments to a manual valve and take a long time to open and close.
How long will it take me to install Drain Master? Can I do it myself?
The average time to do an installation is about 1 hour. You can do it yourself if you possess average mechanical skills. If you take it to a dealership or repair shop, it would take about 1 hour of labor for most RV’s.
Is it OK ot install Drain Master in any position?
The motor must be installed in a position with the motor located between a 10:00 and 2:00 vertical position.
How quickly does the Drain Master open or close?
The Drain Master valve opens and closes in 1 second flat.
If something happens to the motor, can it be replaced?
No, the Drain Master unit is sealed. Note that failure rarely occurs with these valves and here’s why. Heat is the major cause in all motors. Drain Master valves are so fast, there is simply no time for the motor to heat up, thus, it will always be at the outside ambient temperature. If you DO have to replace the sealed unit, you can order the Premium Replacement Valve kit.
What size is the valve?
The Drain Master valve is a 3 inch valve. It attaches to most standard 3″ ABS pipe, available at most hardware stores.
What if I lose power on my RV, will I still be able to open / close the valve manually?
Yes, with a 1/8 Allen Wrench, you can open or close the valve manually. On either side of the Drain Master look for the words, Manual Override, in the upper center area. There is a small domed area that has the hex head located right on the top of the dome.
What kind of switch does the Drain Master use?
It is a toggle switch. Double pole/double throw, commonly called a Rocker Switch. It is Center off, momentary up, momentary down.
How can I use the valve on 1.5 piping?
We offer a set of concentric reducers that enable the 3 inch valve to be used on 1 1/2 inch piping (gray water tanks). Complete installation instructions are available on line as well as instructions are sent out with each kit.
Where can I place the operator switch?
Anywhere it is handy to operate, while emptying your holding tanks. A second switch option is available to place in the bathroom for extended stays in resorts.
Will the valve work with the seals from my manual valve?
Absolutely not! The seals that come with Drain Master are made especially for the Drain Master valve. No other seals should be substituted.
Is there a warranty on the Drain Master
Drain Master warrants our Drain Master Premium electronic waste valves to be free from defects in materials and workmanship for a period of 1 year from the date of purchase. This warranty does not include damage to products resulting from accident, misuse, improper installation and unauthorized alterations. Drain Master’s warranty obligation shall be limited to replacement of the product with a new valve (not reconditioned), which will be your exclusive remedy under this warranty. Drain Master shall not be liable for any special, incidental, indirect or consequential damages whatsoever (including, without limitation, labor or installation charges, damages for loss of business profits, business interruption or any other pecuniary loss) arising out of the use or inability to use the product.
What happens if I hold the switch down too long?
The valve opens in 1 second and holding it longer can slowly wear on the motor windings causing the motor to become weaker over time. As of November 2012 Premium Drain Master operator switches now come with an in line fuse which ensures that your motor won’t be affected by holding it down.