I understood recently that a wet/dry pump (a "shop vac", that is, though not necessarily from that brand) functions by creating a vacuum in an air-tight chamber. The vacuum sucks in anything near the hose, whether it's wet or dry.

I've also seen one manufacturer advertise that some of the wet/dry vacs in their product line can function as a wet pump (in addition to being a wet/dry pump).

I like the idea of using one tool for both functions (in terms of both storage space economy and pocket economy). I'd be using the wet/dry vac to clean the garage floor (maybe 4-6 times a year) and the wet pump function to empty the water on top of a pool cover (somewhere from 250 to 500 gallons, once or twice a year).

Is it indeed the case that a wet/dry vac that can double as a wet pump is capable of continuously pumping? Any wet/dry vac can be used as a 2-stage wet pump (fill, empty, repeat), but doing that 25-100 times in a row is not amusing. Did I understand correctly and some wet/dry pumps can indeed continuously pump water?

I would be perfectly fine with a device that sucks water from the hose, but then allows that water to drain via a syphon from a garden hose, just so long as this process does not need user intervention until it's done.

  • 1
    You should ask about the problem you are trying to solve, rather than over think shop vacs.
    – Tyson
    Jun 24, 2016 at 15:28
  • @Tyson Good point. I rewrote the question to be more direct.
    – Calaf
    Jun 24, 2016 at 15:48

3 Answers 3


There are two solutions:

Wet/dry "Pump" Vac

Look for a wet/dry vac that is labeled "pump" (the manufacturer will likely draw a nice hose with fresh water prominently on the box).

Such wet/dry vacs have a built-in water pump. One model on the market looks like this:

wet/dry pump vac

Universal Pump for Wet/Dry Vacuums

These are add-ons to your wet/dry vacs. Your vac must have a downspout for this option to work. One model on the market looks like this:

pump for wet/dry vac

Neither of these options will allow continuous pumping.

You cannot continuously pump out with the first option because the wet vac will be faster (more powerful motor, 1 1/2" to 2" hose) than the water pump (5/8" garden hose, pump handling just water rather than an air/water mixture).

You will need to pull the hose out of the body of water when the tank is full. Force the power button down to override the shut-off feature for 15 seconds. The water pump will then continue pumping out (at 350 gallons per minute) until the tank is empty. Repeat.

You cannot continuously pump with the second option. You will have to attend to the two pumps. Fill the tank with the wet vac. Turn off. Empty the tank with the water pump. Turn off. Repeat.


Given your use case, you might be better off with a small utility water transfer pump. These are small, connect inline with garden hoses, and are relatively inexpensive. enter image description here


It actually is possible to pump water out of a basement, swimming pool, or any other place that water gathers.

Use a wet-dry water pump accessory and a sealed container by hooking up the discharge port of the pump to a hose and attaching a sealed container to the incoming port. Fill the container with some water, seal it again, attach a hose to the sealed container, then put the hose into the water that needs to be pumped out.

The pump will use the water in the sealed container as a means to create a vacuum and cipher and transfer the water to the pump which relocates the water being pumped. An automatic shutoff can be added to shut the unit off once the water has been removed.

  • A little bit of formatting (maybe a paragraph break or two) would make it much easier to read and understand what you're saying. As it stands, this is just a wall-of-text and is hard to decipher. Mostly what I'm getting is "use a pump accessory" which is what was stated in the accepted answer (check mark) from 5 years ago. Please edit to improve the formatting to make it easier to understand.
    – FreeMan
    Feb 4, 2022 at 13:18
  • Thanks FreeMan, good advice. I just edited it. Feb 21, 2022 at 10:18

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