How we made this guide: picks, prices and specs come from our catalog and the makers' published specs, owner quotes come from customer reviews on our product pages and every guide is checked and edited by Trevor Hall.
To use a shop vac for water, take the dry filter out of the tank, check that the float shut-off moves freely, plug into a grounded, GFCI-protected outlet and work in slow overlapping passes, emptying the tank before it fills. A 15 gallon wet capacity machine like the Mercury Storm WVP-20 at $699.95 handles spills and small leaks well.
Step up to a flood pumper such as the EDIC FloodBuster FB50 when there is more water than you can carry out in buckets, and to a carpet extractor plus drying when water has soaked into the carpet pad. Sewage is a job for a trained restoration crew, not any vacuum.
Quick answer
Can a shop vac pick up water? Yes, if it is a wet/dry model and you set it up for liquid. Time: 5 minutes to set up, then as long as the puddle takes. Difficulty: easy. Tools: a wet/dry vac, a grounded outlet, a bucket and a rinse hose. Browse every wet/dry vacuum we carry or the larger industrial vacuums.
What is a wet/dry vacuum?
A wet/dry vacuum is a canister vacuum built to pick up liquid as well as dry debris. Its motor sits above a sealed tank, the hose feeds the tank and a float shuts off airflow when the tank fills so water does not reach the motor. A shop vac is the common name for the same machine. A regular household vacuum has no such protection and must never be used on water.
The difference between wet and dry use is mostly the filter. On canister machines like the Mercury WVP-20 and Tornado Taskforce 17, the cloth filter is for dry pickup only and comes out for water. Both manuals say so, and we quote them below. Drum vacuums with an external filter work differently: Tornado's JE manual says its jumbo picks up wet and dry waste simultaneously without the need to change any filters.
What you need
- A wet/dry vacuum rated for liquid pickup, with its float and hose.
- A grounded outlet with GFCI protection, or a portable GFCI plugged in at the outlet. On construction sites, OSHA requires GFCI protection on 120-volt, 15 and 20 amp receptacles that are not part of the building's permanent wiring, unless the employer runs an assured equipment grounding program.
- A bucket for emptying, and a hose or sink to rinse the tank.
- A floor tool. The Mercury Storm WVP-20 kit includes a wet floor nozzle, which Mercury's sell sheet calls a squeegee tool, for squeegee-style passes.
- Defoamer, if you will pick up soapy water.
Step 1: Remove the dry filter
Open the latches, lift off the motor head and take out the cloth filter assembly. Mercury's WVP-20 manual says the cloth filter assembly "should be used for dry cleaning only and must be removed when being used for wet use." Tornado's Taskforce manual lists the same swap: for wet suction you "remove the cloth filter from the tank," and for dry suction you insert it.
Two things to check while the head is off. Look inside for debris and check that the float ball moves freely. Both manuals list a stuck float among the causes of lost suction, and Mercury's remedy is to ensure the ball float is moving freely or to empty the tank.
Your machine may use a different wet-use filter or foam sleeve. Follow its own manual for which one to fit.
Step 2: Assemble the head, hose and wand
Set the head on the tank and press the latches down. Push the hose into the tank inlet, slide on the wand and twist the collar to lock it. Fit the floor tool last. The Taskforce manual lists these steps in order and says to remove the hose later by pushing in the red tab and pulling.
Step 3: Power up safely
Water and electricity are the real hazard on this job. Mercury's manual requires a grounded outlet and warns that you should never cut off the grounding prong to fit a two-prong outlet. It says not to handle the plug or the vacuum with wet hands, not to carry the machine by the cord and not to run over the cord. It adds that you should check an outlet with a ground fault interrupter device rather than assume it is grounded.
Keep the cord out of puddles and plug in only after the hose is attached. Mercury's manual also says not to pick up flammable or combustible liquids such as gasoline, not to use the machine outdoors and to return any machine dropped into water to a service center.
Check the machine's rating plate against the outlet. Mercury rates the WVP-20's two motors at 2,000 W in total and gives no amp draw. If that is the input rating, our calculation (2,000 W divided by 120 V) gives about 16.7 A, more than a 15 amp circuit is built to carry. Read the rating plate and use a circuit with nothing else running. If the breaker trips, run one motor only: the sell sheet says each motor has its own switch. The Taskforce 17 is listed at 120 V and 1,200 W, about 10 A by the same calculation. Tornado's JE manual rates the jumbo at 15 amps, says to plug it into a 20 amp wall outlet and calls for an extension cord of 12/3 or heavier, 50 ft at most.
Step 4: Vacuum in slow, overlapping passes
Start at the edge of the water and work toward the center, so you are not pushing the puddle into new areas. A wet floor nozzle held flat gets more water per pass than a round hose end held high. Overlap each pass by a third and finish with one dry pass along the walls and doorways.
If suction drops, the float may have closed. Mercury's manual says that when the tank reaches its maximum level, the sound changes noticeably and airflow through the hose drops. Switch off, unplug and empty the tank. Do not keep running a full machine: Mercury's manual says failure to stop when the tank is full will void the warranty. Tornado's guide lists a full tank as the first cause of lost suction.
Soapy or foamy water is a special case. Mercury's guide lists sudsy or foamy liquid as a cause of water blowing from the vacuum, and its remedy is to add defoamer to the tank. Tornado's guide gives the same cause and remedy.
Corded canister
Tornado Taskforce 17 Wet/Dry Industrial Canister Vacuum (94230)
$525
A 17 gallon tank with 12 gallons of wet working capacity, 90 inches of water lift and a 10 ft hose; a rear drain hose empties it.
Step 5: Empty before the tank fills
The easiest rule: empty at about three quarters full, not when the float closes. Mercury's manual, for dry pickup, says to empty at about 4/5 full because overfilling makes the tank harder to handle. The same logic applies to water, which is heavier still. Our calculation, at about 8.3 lb per gallon: the WVP-20's 15 gallons of wet capacity weigh roughly 125 lb.
- Switch off and unplug first.
- Drain through the machine's own outlet where it has one. Mercury's WVP-20 manual says to unclip the disposal hose, remove its end cap and slowly lower the hose to release the contents into a suitable drain. The Taskforce 17 has a rear drain hose, and the Tornado JE has a drain valve at the base of its drum.
- Otherwise lift off the head and tip the tank into a drain or bucket, with a second person on larger tanks.
- On the Tornado JE, Tornado's manual lists liquid shutoffs as available, so check that one is fitted before a big wet job and watch the drum level.
- Dispose of the water where local rules allow.
Large drum
Tornado JE Single 2.25 HP Electric Wet-Dry Jumbo Industrial Vacuum (95954)
$2,943
A 55 gallon steel drum on a 4-wheel dolly, with a drain valve, 51 inches of water lift and a 50 ft cord. Tornado's manual says it needs no filter change for wet pickup.
Step 6: Rinse and dry the tank and filter
After a wet job, tip out the last water, rinse the tank with clean water and leave the head off so the tank dries. Wipe the body, hose and cord with a slightly damp cloth, as Mercury's care section suggests. Put the cloth filter back only when the tank is dry and you plan to vacuum dust again.
Check the hose and wand for blockages too. A clogged hose is on both makers' lists of causes of lost suction.
Compact stainless tank
Dapper Supply 10-Gallon Wet/Dry Vacuum, 4.0 Peak HP, 3-in-1 Stainless Steel Shop Vac
$155
A 10 gallon stainless tank with 76.3 inches of water lift and 108 CFM. Its 4.9 ft hose and 16.4 ft cord suit small garage and workshop spills near an outlet.
Machine sizes at a glance
| Machine | Price | Tank | Water lift | Airflow | Cord |
|---|---|---|---|---|---|
| Dapper Supply 10 gallon | $155 | 10 gal | 76.3 in | 108 CFM | 16.4 ft |
| Tornado Taskforce 17 | $525 | 17 gal (12 gal wet) | 90 in | 114 CFM | 30 ft |
| Mercury Storm WVP-20 | $699.95 | 20 gal (15 gal wet) | 78 in | 225 CFM | 50 ft |
| Tornado JE single | $2,943 | 55 gal | 51 in | 184 CFM (1.5 in hose, per Tornado's manual) | 50 ft |
| EDIC FloodBuster FB50 | $4,132 | pump-out | 158 in | 110 CFM | 25 ft |
Compare the Dapper figure with care: its "4.0 peak HP" is a peak motor rating and not a running figure, so judge it by water lift, airflow and tank size, as in the table. For picks by job and budget, see the best wet/dry vacuums.
When a shop vac is the wrong tool
More water than buckets can carry
A shop vac fills, then you stop, unplug and empty. A flood pumper pulls water in and pushes it out through a hose, so there is no tank to carry. The EDIC FloodBuster FB50 is rated at 50 gallons per minute with 158 inches of water lift, and it has a stainless steel debris screen basket and an overfill vacuum switch. Its listed draw is 18 amps, more than a standard 15 amp circuit is built to carry, so by our reading it needs a 20 amp circuit with nothing else on it.
In our range, lower-priced pump-out options are the Sandia Sniper 24 gallon flood pumper at $2,892 and the Mytee 7000LX Flood Hog, rated at 66 gallons per minute, at $3,260.
Flood pumper
EDIC FloodBuster Flood Pumper FB50
$4,132
A 50 gallons per minute pump-out, 158 inches of water lift and a 2-year parts and labor warranty for jobs too big for a tank.
Using a wet/dry vac as a water pump
Not on its own. None of the wet/dry vacs in this guide has a pump: each lifts water into a tank that you empty by hand or through its drain. For pumping, use a pump-out machine such as the FloodBuster. For a basement with several inches of standing water, start with a pump, then use the vac to finish the last film of water.
Sewage and contaminated water
Water from a sewer backup or sewage is not a shop vac job. The IICRC S500 water damage standard sorts water into three categories by contamination. It puts sewage in Category 3: water that is grossly contaminated and can contain pathogenic, toxigenic or other harmful agents. That work belongs with trained restoration crews, not a tank you rinse in a sink. Our guide to sewage backup cleanup covers the category in more depth.
Wet carpet
A shop vac can pull surface water off carpet, but water that has soaked down to the pad is still there after a vac pass. The pad needs extraction, then drying with air movers and a dehumidifier. Our guide on how to dry wet carpet after a leak or flood walks through the full job, how to use a carpet cleaning machine covers the extractor side and how long carpet takes to dry after cleaning covers timing.
Common mistakes
- Leaving the cloth filter in for water on a canister like the WVP-20 or Taskforce 17. Both manuals call for removing it.
- Running a full tank. Both manuals list a full tank as the first cause of water blowing out of the machine.
- Ignoring the float. A float stuck shut kills suction, and one stuck open lets water reach the motor.
- Using an ungrounded outlet or an extension cord that is not rated for the load.
- Picking up flammable liquids. Mercury's manual forbids gasoline and similar liquids.
- Leaving a wet tank closed after the job.
Other jobs for a wet/dry vac
With the cloth filter fitted, the same machine handles sawdust, leaves, grit and spilled granules. On wet work it handles washing-machine overflow, a dripping water heater, a spilled mop bucket and rinse water left after scrubbing. For choosing a large industrial model, read the industrial vacuum buying guide.
Frequently asked questions
Can a shop vac pull water out of carpet?
It can pull surface water. Water that has soaked into the pad stays there, so the pad needs an extractor and drying equipment.
Do I need a bag or filter when vacuuming water?
Not the dry cloth filter on a canister vac. Mercury's WVP-20 manual says its cloth filter assembly must be removed for wet use, and Tornado's Taskforce manual says the same. If your model has a wet filter or foam sleeve, use the one its manual names. Drum vacs with an external filter are the exception: Tornado's JE manual says that machine picks up wet and dry waste without changing filters.
What can I use to vacuum up water?
A wet/dry vacuum for spills and small leaks, a flood pumper such as the EDIC FloodBuster FB50 for standing water, and a carpet extractor when water has soaked into carpet. Never a household vacuum.
Can I use a wet/dry vac as a water pump?
Not a standard one. It collects water into a tank that you empty by hand or through its drain. A pump-out machine such as the EDIC FloodBuster FB50 moves water continuously at its rated 50 gallons per minute.
How do wet vacs work?
A motor spins a fan that pulls air through the hose and tank. Water rides in on the airflow and drops into the tank. A float rises with the water and shuts off airflow to the motor when the tank is full.
How do I change a shop vac to a wet vac?
Remove the dry cloth or paper filter, check the float and fit the wet filter or foam sleeve if your model uses one. Then assemble the hose and wand as usual, and plug into a grounded, GFCI-protected outlet.
How do I wash a wet/dry vac filter?
Wash it if the maker says it is washable, and let it dry fully before it goes back in. Mercury's sell sheet says the WVP-20 cloth filter is easy to remove and wash, and Tornado's Taskforce brochure calls its filter washable. Between washes, Mercury's manual says to shake it out, tap it gently or blow it clean. Replace a torn filter: both makers list that as the fix.
Pick up water faster
