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

4.6 Rating 125 Reviews
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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,

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“Not silent, but quiet, am using it for a shower and sink. It shoots up nearly 8' before entering the house plumbing. Goes on and off regularly during a shower or sink wash. It does not stay on. I ran mine on it's own 15 amp power line from a satellite breaker, if running with lights, it may cause dimming during operation.”
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Posted 7 years ago
“Works amazing”
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Posted 7 years ago
“This pump works wonderfully for a basement shower or sink”
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Posted 7 years ago
“My Sanivite arrived quickly and in perfect order. It took me almost all day to install it, but it was relatively easy, just time consuming. It works very well. I have two vanity sinks and a shower feeding into it and it handles them with ease.”
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Posted 7 years ago
“We installed this under an apartment sink about a week ago and are very happy with it so far. It is only handling dishwater from the sink, but is very quiet and has short pump cycles. The first one that arrived did not work out of the box, but SaniFlo were quick to send a replacement. Would definitely recommend.”
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Posted 7 years ago
“Working perfectly! , love it and very quiet , installed on a pedicure massager chair and cant be better , is inside and not even bothering no one on the whole place, is hard to tell , great great great! , installation wasn't that bad since plumbing was accessible and all parts where right on, no leaks since first test ,.”
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Posted 8 years ago
“This was our solution to a basement shower where no drain was available. Works great. Reliable. Suitable for its intended purpose. One thing learned if you dont use shower for a while the trap dries out and you get some mild sewer gas push back. Running shower water for 1 minute fills trap again and all is good. I would recommend this to anyone looking for a basement bathroom where you dont want to rip up the floor to put in drains.”
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Posted 8 years ago
“This unit did exactly what I needed it to do. Delivery was prompt and came well packaged. Installation was a breeze. Thanks for a good solution to my problem.”
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Posted 8 years ago