How To Use A Shop Vac For A Water Pump (Do This!)

Dennis Howard
by Dennis Howard

The unthinkable happens and you find that there are now several inches of water in your basement. Short of finding a submersible pump or calling a clean-up company, what can you do? If you have a shop-vac with pumping capabilities, you may already have the answer to your problem.

Using a shop vac as a water pump depends on the manufacturer of the shop vac. The shop vac must have a discharge port built into the tank. In general, using your shop vac as a water pump requires you to remove the filters, attach a garden hose to the outlet on the tank, and turn on the shop vac

Having a shop vac around the house that has the option to pump water can be a boon. Not only do you get the benefits of a shop vac, but you also can move water quickly and easily from one place to another. Shop vacs with pump capabilities are versatile and handy tools.

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Using Your Shop Vac to Pump Water

There are many brands of shop vacs that come equipped to pump water. Each manufacturer has its specific instructions for setting up and using a shop vac as a water pump. For the exact directions to use your shop vac as a water pump, consult the user’s manual. The directions below apply to all shop vacs in general and may differ slightly from model to model.

Step 1: Does Your Shop Vac Pump Water?

Be sure that your shop vac can act as a water pump. Most of the shop vacs capable of pumping water have a discharge outlet on the back of the tank. This discharge outlet fits a garden hose that carries the wastewater away from the shop vac for disposal.

Step 2: Play it Safe – Electricity and Water Don’t Mix

Before you go any further, consider how you will be using your shop vac to pump water. You must plug your shop vac into an outlet. Never plug in a tool or appliance if you are standing on a wet surface or in standing water.

Find an outlet in a dry area to plug in your shop vac. Make sure the outlet is well-grounded. The outlet should be part of a GFCI circuit as well. Don’t use an extension cord. Electrocution is possible if the end of the extension cord slips or falls into the wet area or standing water.

Step 3: Remove the Filters from Your Shop Vac

Open your shop vac and remove the paper filters from the vacuum. Some shop vacs that can pump water have a float mechanism inside the tank. This float valve will shut off the motor if the water gets too high inside the tank.

Replace the top of your shop vac and make sure it is seated properly and the latches are tight.

Step 4: Insert the Pump Attachment if Required

Some shop vacs require a special attachment fitting inside the vacuum tank to operate as a pump. The pump attachment may be an accessory you need to purchase from your home improvement store. Follow the directions in the user’s manual or that came with the attachment.

Step 4: Attach the Garden Hose to the Discharge Outlet

Attach the garden hose to the discharge outlet on the tank of the shop vac. Some models of shop vac have a valve on the discharge outlet. Open the valve if the shop vac is so equipped. Opening the valve will allow the shop vac to discharge the water through the garden hose.

Stretch the garden hose to a safe discharge area. Avoid any kinks or tight bends in the garden hose. Depending on the water you are moving, avoid putting contaminated water on your landscaping. Many people pump wastewater into a toilet.

Step 5: Check your Electrical Connections

Check your electrical connections one more time. The electrical plug should be plugged into a GFCI circuit and properly grounded. If you must stand in water to operate the vacuum, take great care not to touch any metal and handle the plastic hose on the shop vac.

Step 6: Start the Shop Vac and Go to Work

Turn on the shop vac and get to work. Be sure to watch the tank on your shop vac. Remember that you may be sucking up water through a three or 4-inch hose and that the water is going out through a 5/8 inch garden hose.

The vacuum can easily get overwhelmed and either overflow or shut itself off. It is usually a good idea to have someone watching the other end of the water hose, especially if it is dumping into a toilet.

Step 7: Clean out the Shop Vac

Be sure to clean out the shop vac when you finish the job. The tank may have accumulated debris and dirt. Take the tank outside and wash it out thoroughly. Replace the filters and store your shop vac ready for its next use.

Things to Remember About Your Shop Vac

Shop vacs are handy tools around the house and in the shop. However, there are certain things you need to remember about your shop vacuum to get the best performance.

Your Shop Vac Isn’t a Pump

Even if your shop vac has a discharge opening, it isn’t a true pump. The height the shop vac will raise water is limited. You should not use your shop vac to pump the water from ponds or swimming pools. For large accumulations of water, a submersible or sump pump is a much better choice.

Keep the Air Flowing

Many shop vacs depend on the airflow through the vacuum to cool the motor as it runs. When you are sucking up large amounts of water, the airflow through the vacuum is restricted. Less airflow can cause the motor to overheat and fail.

When using your shop vac to pump water, the best method is to suck water for a while and then allow air to flow through the vacuum to keep the motor cool. Allowing air to flow into the shop vac also gives the water time to drain through the much smaller garden hose discharge.

Avoid Sucking Up Large Debris and Dirt

If possible, avoid sucking up floating debris and dirt as you are pumping water with your shop vac. The debris and dirt will remain in the tank of your shop vac. This debris can damage the tank or the motor under some circumstances.

The debris may lodge in the vacuum hose and stop air and water flow through the vacuum. If there are large amounts of debris or dirt in the water, a dirty water pump is a better option. These dirty water pumps come with filter screens and can handle moving debris through the pump.

Read the Directions

Before you decide to use your shop vac as a water pump, familiarize yourself with the manufacturer’s recommendations. The user’s manual that came with your shop vac should have step-by-step directions. Following these directions is the best method of removing larger quantities of water.

Opt for a Foam Filter if Available

Some shop vac models have foam filters as an option. These foam filters are useable when sucking up water or using your shop vac as a pump. The foam filter can protect the motor of your shop vac and help eliminate problems with debris and dirt.

Keep the Duty Cycle in Mind

Most shop vacs have a 50 percent duty cycle. A 50 percent duty cycle means that your shop vac should not run more than 30 minutes out of every hour. Continuous use will eventually damage the motor and other controls and ruin your shop vac.

Work Safely

Following a few simple rules will allow you to operate your shop vac as a water pump safely.

  • Always plug your shop vac into a GFCI protected circuit when in a wet environment
  • Don’t use extension cords if you are vacuuming accumulated water
  • Never operate your shop vac barefoot. As tempting as it may be if there is standing water, this is a dangerous practice
  • Wear rubberized gloves to help prevent electric shocks
  • Always protect your eyes with safety glasses or goggles
  • Follow the manufacturer’s recommendations for all shop vac operations.
  • Wear hearing protection for extended uses. Shop vacs can produce levels of sound that can damage your hearing over time.

Keep the Amount of Water to A Minimum

As we have stated, shop vacs are not water pumps and not meant to move large amounts of water. Trying to pump extensive amounts of water from a basement or other area can damage your shop vac and seriously shorten its life.

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Getting the Most from Your Shop Vac

Shop vacs are incredibly versatile tools and have a place in most homes and shops. Using your shop vac as an occasional water pump adds to the value of having a shop vac around. When done safely and with an understanding of the shop vac limitations, these appliances can be lifesavers.

We hope that this article helps you understand how to use your shop vac as a water pump. Shop vacs will never take the place of a real water pump, but in an emergency can be pressed into service. As always, work safely.

Dennis Howard
Dennis Howard

Dennis is a retired firefighter with an extensive background in construction, home improvement, and remodeling. He worked in the trades part-time while serving as an active firefighter. On his retirement, he started a remodeling and home repair business, which he ran for several years.

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