Login
Start Free Trial Are you a business? Click Here

Saniflo 21 Residential Water Pump, Grey,1/3 HP Reviews

4.6 Rating 125 Reviews
Read Plumbing Supply and More Reviews

The Saniflo MPN 21 residential water pump transforms basement remodeling projects by eliminating traditional drainage limitations through its specialized 1/3 HP motor configuration. This grey-colored thermoplastic housing unit measures exactly 8.75 inches in height, 9 inches in width, and 10.25 inches in depth, positioning itself as the compact solution for residential drainage challenges where gravity flow proves impossible.  Weighing 13 pounds, this Saniflo pump delivers 18 gallons per minute discharge capacity at its maximum 14-foot vertical lift specification, making it the definitive choice for basement apartments, laundry installations, and remote kitchen additions where conventional drain systems cannot reach the main sewer line. Unlike standard sump pump configurations designed for groundwater removal, the MPN 21 features three strategically positioned 1.5-inch inlets—two low-profile side inlets with integrated check valve protection and one top-mounted inlet—enabling simultaneous wastewater collection from multiple fixtures without requiring complex manifold assemblies.  The unit's 120-volt, 60-hertz electrical specification draws a maximum 4.5 amperes during operation, qualifying it for standard residential circuit integration while maintaining CSA certification under both IPC and NSPC plumbing code standards. Precision-Engineered Oil-Filled Motor Technology Delivering Maintenance-Free Performance The permanently sealed oil-bath motor assembly within the Saniflo 021 eliminates traditional maintenance intervals found in conventional drain pump applications. This 0.3 horsepower induction motor operates at precisely 3,600 revolutions per minute, driving a direct-coupled impeller through a single spindle shaft that minimizes mechanical complexity and potential failure points.  The oil-filled enclosure surrounding the motor provides continuous lubrication, thermal protection through efficient heat dissipation, and acoustic dampening that reduces operational noise to just 44 decibels measured at three feet—quieter than most residential dishwasher cycles and significantly below the threshold requiring hearing protection in occupied spaces. The thermoplastic housing material surrounding the motor assembly resists corrosion from prolonged wastewater exposure while maintaining structural integrity at operating temperatures up to 140 degrees Fahrenheit.  This temperature threshold accommodates hot water discharge from washing machines, dishwashers, and utility sinks without requiring cooling periods or thermal protection devices. The polyethylene construction also provides chemical resistance against common household cleaning agents, laundry detergents, and kitchen effluent containing mild acids or alkaline compounds. Engineering specifications reveal the motor's 30-microfarad capacitor rating ensures consistent starting torque under varied load conditions, preventing the motor stall issues that plague less sophisticated residential pump designs.  The pressure switch activation mechanism responds to water level changes within the 2.75-gallon capacity chamber, triggering motor engagement only when sufficient volume accumulates for efficient discharge cycles lasting between two and ten seconds depending on horizontal pipe run configurations and vertical lift requirements. Three-Inlet Configuration Maximizing Installation Versatility Across Residential Applications The Saniflo MPN 21's triple inlet design accommodates diverse fixture combinations without requiring additional collection pits or intermediate pumping stations. Both side-mounted 1.5-inch inlets incorporate factory-installed check valves that prevent backflow during system operation, eliminating the need for separate valve installation and reducing potential leak points in the drainage assembly.  These low-profile inlets position just above the unit's base, facilitating gravity drainage from floor-level shower bases constructed on minimum 6-inch elevated platforms using dimensional lumber framing techniques. The quarter-inch per foot slope requirement toward the pump ensures consistent flow without standing water accumulation in horizontal drainage runs. The top-mounted inlet provides alternative connection routing for fixtures positioned above the pump housing,

Visit Product Page
“We moved our washer and dryer to the basement and this was an great solution that didn't require a bunch of expensive plumbing. Great alternative!”
Helpful Report
Posted 3 years ago
“I have a short lift to reach the drain from a wash sink. I have no complaints about the operation works well. I’ve only been using it for a month. I hope it has many years of good service.”
Helpful Report
Posted 3 years ago
“Sound is a bit annoyying when it starts and may be it's normal as it starts almost instantly when i thrn on the sink tap and the inflow is bit less than what it's trying to pump out. But it felt more smooth and handled well when I've tried with dishwasher turned on. My city plumbing inspector recommended this as he was also using this and am happy to get this and is small cute and compact to fit under the sink in the cabinet. Hopefully it'll last long without any issues.”
Helpful Report
Posted 3 years ago
“Works great for pumping out walk-in bath tub that is in a finished basement”
Helpful Report
Posted 3 years ago
“PROBABLY FINE FOR SHOWER-BUT NEEDED FOR A BASEMENT SINK AND FINALLY GOT IT INSTALLEDABOUT 2 MONTHS AGO WITH 2 CALLS TO REPAIR MAN, LEAKING. DRAIN NOW WORKING OK WITHOUT THE PUMP. WOULD APPRECIATE A CREDIT OR REFUND.THANKS”
Helpful Report
Posted 4 years ago
“Works fine with one sink. Didn’t came with all external parts. The good thing is u dont have to get a check valve coz it cones with it. Just a little noise when pumping out the waste water.”
Helpful Report
Posted 4 years ago
“Works very well!”
Helpful Report
Posted 4 years ago
“The chord wouldn't reach my outlet which wasn't even 5ft away. Please update to include at least 6ft chord”
Helpful Report
Posted 4 years ago