How to vacuum water with a shop vac

Bryony Gilbey

Versatility in tackling clean-ups and rugged construction make DeWalt's 20 Volt Max shop vac a perennial customer favorite.

Remove water with a wet/dry vacuum 

When an area of your house gets flooded, whether from heavy rainfall or the dishwasher or washing machine springing a leak, the effect can be devastating. If left too long, water damage can be permanent, so it’s important to get that water out of your home as soon as possible. A wet/dry shop vacuum, or shop vac, is the best way to achieve this. It’s also useful for emptying out water from a blocked tub or sink or anywhere water is sitting and not draining. It can handle big dry messes, too.  

What is a shop vac?

Many major tool-making companies produce shop vacs. They are the go-to machine for cleaning up major messes. They have a simple, easy-to-clean design consisting of a powerful motor atop a large canister. The canister is divided into two sections (one for water, the other for dry detritus) and is almost always mounted on casters for easy maneuverability. The vacuum hose is long and flexible and comes with several different cleaning heads. 

Choosing a shop vac

If you don’t already own a shop vac and need to purchase one, the first step is to assess your needs. Most shop vacs have a tank capacity of 4- to 10-gallons, although a few will take in as much as 20 gallons before you have to empty them. Other, smaller capacity shop vacs are usually specifically designed to handle small vacuuming tasks like emptying a clogged toilet or pipe. Opting for the largest canister machine might seem to make sense for a big clean-up job, but large, water-filled canisters are very heavy and can be difficult to lift and empty. If heavy lifting is difficult for you, you may want to consider a smaller capacity machine. 

The shop vac cleaning process

Once you have your shop vac and are ready to start cleaning, you must make sure it is set up to handle water vacuuming.

Remove the liner

If the shop vac was last used to vacuum up dry debris you will need to open up the top and remove the plastic liner or bag. You will not need a liner to vacuum up water. 

Change the filter

A shop vac uses different filter types for the wet and dry functions. The dry function uses a paper-based filter which would break apart in water. For the wet function, filters are usually made from some kind of foam which will absorb the liquid undamaged. Check which type of filter is in your machine and change it as needed. 

Attach the appropriate vacuum head

There is usually one main attachment that is used to clean up water. It resembles the wide, flat head of a regular vacuum cleaner and is designed to navigate floors.

Plug the vacuum into a GFCI outlet

Because of their function, almost all shop vacs come with a double layer of insulation so that you can safely plug them into any outlet. However, any time you mix electricity and water it can be dangerous. It is recommended to connect your shop vac to a ground fault current interrupter outlet as an additional safeguard when possible. A GFCI outlet will shut off power at the outlet if a fault is detected, preventing you from being electrocuted. 

Start vacuuming  

Once you have turned the shop vac on, position the attachment head on the surface of the water and start vacuuming. If you are vacuuming up a large quantity of water, listen out for the changing sound of the vacuum motor to indicate that the canister is full. Move the vacuum across the room in a consistent pattern until all the water has been removed.

Regularly empty the canister 

You don’t have to wait for the canister to be completely full to empty it. Turning the machine off and emptying a less-than-full canister might make for more frequent trips to the sink but it can also make the job more manageable, particularly if you have physical constraints and aren’t used to carrying heavy loads. If you are vacuuming up dirt and water simultaneously, you may want to empty the canister through a large sieve to prevent debris from clogging up your drain. 

Clean your shop vac for storage

After you have finished vacuuming up all the water, it is important to thoroughly clean your shop vac before putting it away. To achieve this, it is recommended to rinse the canister twice; the first time with a bleach and water solution, then with plain water. Finally, make sure all the parts are completely dry before putting the shop vac in storage to avoid the buildup of mold and mildew in the machine itself. This includes the hose, which can be hung vertically to make sure all the water has drained out. 

Using a shop vac is a highly efficient way to get rid of standing water. Shop vacs are very simple machines to use and maintain, and with proper care will be useful for many years of tough clean-up jobs.

Bryony Gilbey is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money.

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