Drain Pumps 101: What is a Drain Pump System and How Does It Work?

Featured Article | February 2023

The affordable, labor-saving solution for creating drainage for your new island sink, outdoor kitchen or laundry room.

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Homeowners across the country are pointing to the addition of an island as the must-have upgrade for kitchen renovations this year. Additionally, they are embracing the new outdoor kitchen trend, and what’s not to love about it? Adding an outdoor kitchen can dramatically alter your hosting experience. 

Adding a conveniently located laundry room could be another project on your to-do list in 2023. Your project might involve adding a remote laundry room to your basement, attic, or garage. But you have no idea where to start, and you cringe at what it will cost. You might even be wondering: “Is it possible?” 

Common challenges have historically held homeowners back from adding islands, outdoor kitchens and laundry rooms – such as the difficulty and high costs associated with adding plumbing drainage in the center of the room or outside where no existing drains exist. 

However, these challenges are now easier to solve than ever.

Plumbing problem solved

Of course, you could add an island without plumbing. But having a sink in an island can improve the workflow in a kitchen and open up counter space elsewhere. 

However, plumbing an island can be problematic if your home is built on a slab or a crawl space. The cost of cutting through concrete and adding piping can be prohibitive.

The same applies to adding a sink to your new outdoor kitchen or moving your laundry room to a new location. 

Above-floor drain water pumping systems can solve these problems. Manufacturers like Saniflo make various pumping systems that can eliminate the need to cut concrete or break through new flooring, and reduce the cost of installing plumbing in a new island, outdoor kitchen, or laundry room.  Saniflo developed its innovative, “above-floor plumbing” technology more than a half-century ago and has led its commercialization worldwide. Today, the company markets macerating technology through 27 subsidiaries in 70 countries and has sold more than eight million units worldwide since 1958.

Cutting through concrete to install plumbing can easily account for 50 percent of your renovation budget. You may abandon the idea of a sink or laundry room altogether when facing that kind of cost. 

Above-floor drain pumps allow you to add a sink or washing machine, hide a single drain pipe in a decorative column, and achieve the kitchen or laundry room of your dreams at a fraction of the expense of traditional plumbing options.

What’s a drain pump and how does it work?

The primary advantage of a drain pump system? It can be installed on top of any finished floor in the home. This allows you to place a new sink or washing machine wherever it is most convenient. 

Whatever the placement, it can be accomplished without the need for costly excavation of the floor to install a drain line. Walls and floors remain intact, and installation is performed quickly and economically with minimal disturbance to room layout. A sink or washing machine can be operational in half a day. 

Instead of routing gray water through below-floor drainage lines to sewage access or a sewage ejector, the wastewater from the fixture drains through gravity into a drain pump. 

Saniflo offers a variety of drain pumps that are made for both residential and commercial applications that move gray water away from fixtures.

Step-by-step of the drain pump system process:

  1. The gray water drains into one of the low inlets on the drain pump via gravity flow. Discharge water from a second fixture, and even a third, can also drain into the unit via one of its other two inlets.
  2. The inside of the drain pump consists of a pressure switch and circuit board assembly, which starts and stops the unit, and the motor, which drives the pump.  The motor is sealed for life in an oil-filled enclosure.  A spindle/shaft drives the impeller; as a result, moving parts are kept to an absolute minimum, reducing the need for servicing.  
  3. Once gray water enters the chamber, it is pumped away into the sanitary sewer via a 1-inch ,  1.5-inch,  or a 1 and a 1/4 -inch rigid discharge pipe. 
  4. Depending on the type of system, the unit will pump the effluent upward and/or horizontally (with gravity fall). Note: The allowable discharge length depends on the particular Saniflo unit you are installing. 
  5. A discharge elbow on top of the drain pump can be turned either to the left, to the right, or towards the back, depending on the configuration of the discharge pipe run. A non-return check valve, which comes already integrated with the discharge elbow, prevents backflow into the unit. 
  6. Once the water is discharged and the water level in the container goes down, the air pressure switch deactivates the unit until the next time water enters the unit.  Depending on the unit, the normal operating cycle for a drain pump can be as short as 2 – 10 seconds and is governed, again, by the pipe run configuration. Power consumption is therefore minimal.
  7. Saniflo drain pump units are designed with a vent connection on the lid, because all plumbing codes require connection to a vent system. Please note that the vent system should be a two-way air vent. The use of mechanical vents, air admittance valves or similar devices are not permitted, as these are considered one-way systems.

IMPORTANT: The information above is a general description of how a Saniflo drain pump works. Be sure to reference the product and technical data sheet for the particular Saniflo system you are installing to ensure correct installation and function.  

Check out this video by Home RenoVision DIY showing how he installed a Saniflo Sanivite drain pump for a new laundry room or this video by The Remodeler’s Life of a  basement bar sink install.

Now that you have a better understanding of what a drain pump is and how it works, it’s time to select the appropriate drain pump system for your application.

Which Saniflo drain pump is right for your project?



  • Used to pump gray water away from a variety of fixtures in residential applications, the Sanishower discharges the waste up to 12 feet vertically and/or 100 feet horizontally.
  • It is ideal for medium-duty applications.
  • In addition to sinks, the Sanishower will also accept and discharge the gray water from other sanitaryfixtures, such as a shower, a urinal, etc. 


  • The Saniswift is used to pump gray water away from a variety of fixtures in residential applications. 
  • It is able to discharge waste up to 14 feet vertical and/or 140 feet horizontal. 
  • Powerful and economical, the Saniswift features a compact design and multiple inlets.
  • In addition to handling drainage from a sink, the Saniswift will also accept and discharge waste water from a variety of other sanitary fixtures, such as a laundry sink, a shower, or a urinal. 
  • The Saniswift can also accept gray water from a washing machine through an indirect connection such as a laundry sink.

Saniswift Pro

  • The Saniswift Pro can handle tougher applications than Saniflo’s Saniswift unit and  is used to pump gray water in a variety of residential and commercial applications.  The new, IAPMO-listed Saniswift Pro prominently displays the Uniform Plumbing Code logo, marking its acceptance in theWestern United States where UPC complianceis a must.
  • It is able to discharge the waste up to 14 feet vertical and/or 140 feet horizontal.
  • Powerful, yet economical, the unit features a compact design and one 1.5-inch inlet at the top; and two, 2″ inlets, positioned low on the sides of the unit, the better to accommodate plumbing connections.  The unit pumps the effluent upward to 14 feet and/or 140 feet horizontally (with gravity fall).
  • In addition to a sink, the Saniswift Pro will also accept and discharge the gray water from other sanitary fixtures, such as a laundry sink, a shower, or a urinal. 
  • The Saniswift Pro can also accept gray water from a washing machine through an indirect connection such as a laundry sink.
  • Servicing can be done without disconnecting any piping to the unit. Made of rugged, high-density polyethylene (HDPE) to resist corrosion from harsh chemicals, the Saniswift Pro encasement has a top cover with two removable screws, providing ready access to all electrical components inside. The pump motor can then be quickly lifted from within to remove any foreign objects in the impeller.

Note: When adding a shower, a base will have to be constructed. This base should be 2″ x 6″ (minimum) or 2” x 8” (recommended) on edge to permit the installation of a P-trap and the required ¼-inch per foot gravity flow towards the pump unit.


  • Sanivite is designed for kitchen sink applications as it can handle small debris from a kitchen sink as well as small amounts of grease. The Sanivite is able to discharge gray water away from a variety of fixtures, including a dishwasher, up to 16 feet vertically and/or 150 feet horizontally.
  • The unit has two, 2-inch inlets, with built-in check valves to handle the drainage from any shower,  bathtub, urinal and whirlpool. 
  • It can also accept gray water from a washing machine through an indirect connection such as a laundry sink. 
  • The unit discharges the waste through  a 1-inch ,  1.5-inch,  or a 1 and a ¼ -inch rigid discharge pipe , using the discharge elbow with a built-in check valve that is provided

Sanicom 1 & 2

  • The Sanicom 1 has a single (“simplex”), one-horsepower motor. Its more powerful companion is the Sanicom 2, which is equipped with a pair of two-horsepower, 220-volt motors (“duplex”) for handling multiple commercial fixtures that must process large volumes of high-temperaturewater, grease or chemicals. 
  • The Sanicom 2 duplex drain pump can move up to 140 gallons of fluid per minute,with both pumps automatically activating simultaneously when the incoming flow rate exceeds that of a single pump.  
  • The Sanicom 1 and 2 can handle fluids up to 194°F, making them ideal for industrial-scale dishwashers, commercial washing machines, hydroponic crop growing, as well as any other commercial and industrial applications requiring wastewater evacuation.


Saniflo offers a wide range of drain pumps, macerating and grinding pump systems, as well as lift stations and condensate pumps. With Saniflo above-floor plumbing technology, you decide where your new kitchen, laundry room or bathroom goes. You are no longer limited to locations where downhill drainage or gravity evacuates waste. You don’t even need to be near the main waste pipe (soil stack). A drain pump system is a smarter, faster and cleaner way to install a sink or washing machine. 

The picture you have in mind of transforming your unused space is now easier to realize than ever — and without breaking the floor or the bank.


SFA SANIFLO U.S.A. – whose parent company originated macerating plumbing technology — offers a complete line of waste and drainage pumping systems for residential and commercial applications. Saniflo developed its innovative, “above-floor plumbing” technology more than a half-century ago and has led its commercialization worldwide. Today, the company markets macerating technology through 24 subsidiaries in 50 countries and has sold more than seven million units worldwide since 1958. Saniflo markets through independent sales agents throughout North America, and the product line is currently available at distributor and dealer locations throughout the United States and Canada.

For more information, contact Saniflo at 1-800-571-8191. Or visit the Saniflo website at saniflo.com.

For editorial assistance, including photography, contact John O’Reilly c/o GreenHouse Digital + PR: 815-469-9100 or [email protected].



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