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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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“I bought this pump to hook up with one shower and two sinks in basement projects. The first pump received was damaged during shipping. plumbingsupplyandmore made the replacement trouble free. The replacement pump was in good shape. The shipping package overall is not very good for a pump mainly made of plastic. The pump was in a small just fit cardboard box with no space for packing material nor outside box for double protection.The second pump has been working fine with lower noise and vibration than expected. Very happy about that.The kits including everything that needs for the plumbing connections near the pump. You need buy other plumbing parts for the hook up. However, the parts came with the kits are not good quality. The elbow and pipe clamps are slow leaking after connected together. I had to replace them with similar parts from hardware store to fix the problems.”
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Posted 8 years ago
“This is a great little pump that fits under the utility sink and removes my washer waste water with no trouble or problems...just love it.”
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Posted 8 years ago
“Worked perfect in our application , installed utility sink for washing machine to drain into then to the pump and out to the septic tank. Works better than anticipated”
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Posted 9 years ago
“We just upgraded out basement into an accessory apartment for my daughter and this was a vital part to making that possible. We have this installed in her kitchen and it handles all the crap that comes from the sink and dishwasher. It's relatively quiet (it's a pump, so you will get a little noise) and installation seemed pretty straightforward (our builder put it in but I didn't hear his helper cursing, which was a pretty good indication that the installation went without a hitch!).All in all a great solution for basement kitchen installations where small particles and grease may be an issue for other water pumps.”
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Posted 9 years ago
“Kinda loud but works.”
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Posted 9 years ago
“Savior of the water drainage system. Small and good looking and can be placed anywhere. Does make intermittent gush of water sound when it pushes the jet out through the 1" outlet pipe. Each push last about 2 seconds. 6months in and so far so good. Cannot complain.”
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Posted 9 years ago
“Does just what it says it does.”
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Posted 9 years ago
“We have installed but not used this pump. It seems to work fine on the trial,so looking forward to having it in use.”
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Posted 9 years ago