Self-emptying Wet Vac




About: I'm the guy in the back of the warehouse who fixes all the stuff that people break. Right around those shelves full of parts and newly broken things. Theater lighting is my day job.

With the upcoming spring flooding scheduled, I turned my twisted brain to a better solution to removing the last inch of water from my basement. The basement doesn't flood often enough to want to spend the big bucks on a sump pump system, and it hasn't yet flooded deep enough for the usual portable sump pumps to be effective. Removing the water with the trusty shop vac was what I ended up doing. But having to stop and empty the blasted thing every few minutes got tiresome.

So I saw those 20 dollar wet vac heads that go over a five gallon bucket at the local big box home improvement store. I got one of them, a bucket, and a generic replacement toilet flapper valve.

Drill a hole near the bottom of the bucket of the right diameter to accommodate the particular flapper valve you got. 1.5 inches worked for me, but a little bigger or a little smaller should work okay if that is the size hole saw you already have. Smooth the inside edge of the hole so it will make a good seal. The flapper valve should be one of the flexible rubber ones so it will conform to the curvature of the bucket. Otherwise you will need to build up the edges of the hole to make a flat sealing surface.

Glue the flapper valve to the outside of the bucket such that it will seal in the hole when the vacuum starts sucking. You could, of course, use duct tape for this, if you want that real redneck engineering look. It should hang down over the hole close enough that the suck of the vacuum will pull it tight when you turn it on.

Put the suction top on the bucket and test your seals. It should suck up water normally via the hose until you turn off the vac. The water pressure should then push the valve open and the water will flow out. Now all you need is a long vacuum hose to extend the suck to where the puddles are. You can find this in the pool section of your local stores.

To use, setup the vacuum bucket outside or in a sink or on top of a toilet. Use the long pool hose to allow you to suck up the water anywhere within the reach of your hose. If your cheap vacuum bucket head, like mine, uses a floating plug to keep the water from entering the motor, you still have to go back to the thing and power cycle the motor to resume the suck. If you already own a better wet vac with an actual float switch that turns off the motor, you can make this modification to your existing vac. If you don't want the self-draining feature the rest of the year, you can temporarily plug the hole with a plumbers stopper.

The most expensive part is the long pool vacuum hose at 45 bucks. Everything else was 25 bucks and about an hour of time.

A friend suggested using a wireless remote control power switch, such as an X-10 system or a leftover wireless christmas light controller to save the walking back and forth to power-cycle it each time it fills up. If you have one laying around, this is a grand idea. Make sure it has enough capacity to operate the vacuum without burning up. Read the amps sticker on the vac and the controller. The controller should have more amps capacity to be safe.
Wired remote controls or dragging the extension cord around with you to unplug would be dangerous, as you will be operating the switch while standing in a puddle of water. Electrocution, I'm told, is really painful, until you die. So, that's a really bad idea. Be safe, and hopefully you will never need this in your house.

Step 1: It Works!

So, here it is, four years later. It worked great that whole time, there was no water in my basement until a couple days ago, when the hot water tank sprung a leak. It was a small leak, as such things go, but it was raining in my furnace room, as the leak was in the expansion tank that had been plastered into the ceiling back when the house was built, above the plaster. So water was dripping out anyplace there was a crack or screw hole.

So, after I shut off the water supply and bled off some of the water from the furnace, I dug the wet vac out and set it up outside the basement door. As it turned out, the 40 foot long pool vacuum hose was juust long enough to reach the edge of the biggest puddle. So after slurping up that puddle, I took a quick trip to the store where all the pool accessories were on a 20% off end of season sale, and got another 30 foot long hose and a coupler fitting. This allowed me to slurp up all the rest of the puddles.

Walking back out, all I had to do was turn off the vacuum, and the dirty water immediately flowed right out as planned. turned it back on and it sealed back up and slurped up more puddles just fine.

When I checked in the morning, the rain in the furnace room had stopped, and the floor was merely damp. Success!



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    6 Discussions


    2 years ago

    I have a shop vac with a drain and actually a pump attached to empty the water. The pump works a little faster than just the drain alone, but not that much faster. But not having to empty that thing, just being able to stand there while it drains, is a HUGE help. Try this, folks!


    6 years ago on Introduction

    Best of luck. So far it has worked for me. The basement has not had water on the floor since I made it. *laughs*


    6 years ago on Introduction

    This is a great idea. Can't wait to make one.


    8 years ago on Introduction

    Also If you could give a few more pics of the project, I mean the point is clear but maybe some Video of it working? Other than that I love it!

    1 reply

    Reply 8 years ago on Introduction

    I'm currently limited to crappy cellphone pictures. The one picture I'm using was the only really usable one. The others had shadows, glare and intruding fingers blocking the lens. Next nice sunny saturday we get, I'll see if I can setup some sort of demo for photography purposes. Not this weekend, the weatherguessers are calling for rain.

    The only key parts are the toilet flapper placement and the use of a long pool vacuum hose. My brother suggested using flexible low voltage electrical conduit. It comes in various diameters and he says they use it for temporary drainage on construction sites all the time. But since it isn't on the shelf at the local Blue or Orange store, I decided not to include that.

    Thanks for the comment. hope you don't actually need to use it. *smiles*


    8 years ago on Introduction

    Wow! Never thought of this, but the simplicity makes it Awesome!
    Thanks for sharing!