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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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“Saved breaking up the basement cement and the product displaces all of the shower water in a quick and quiet manner. Great product for installing a shower in a basement location without major work to install a floor drain in concrete.”
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Posted 9 years ago
“Easy to install so far so good”
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Posted 9 years ago
“The pump itself works really well. Two issues bring the review down. First, the check valve is really low quality (we are concerned about failure) and is prone to leaking around the clamps. The second problem is that the cord is really short. We would have preferred to pug it in further away from the sink. Yes, we put this on a outlet that will trip off it it gets wet, but I would rather have installed thae outlet well away from where it could get wet from the sink and far from the crappy check valve. In both cases, these issues are simply an issue of cutting corners with quality.”
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Posted 9 years ago
“Does what it supposed to do.”
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Posted 9 years ago
“works great for basement urinal”
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Posted 9 years ago
“I have had this unit installed for 2 years in a kitchen that serves my family of 7 and it has worked flawlessly for us. We try to be very conscientious about how we treat the pump and have strainers on both sides of the sink and we never pour grease down the drain. The only problem I have had was one of the screws holding my drain line clamp in place sheared off and the unit was able to disconnect from the drain line, it made a mess but was an easy fix. I noticed some reviewers complaining about the clarity of the installation instructions but I found them to be on par with other instructions I've encountered on European made goods. They tend to use a lot of pictures and few words so the installation book isn't written in 37 different languages. I would highly recommend this product for any situation where traditional drain lines can not be run.”
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Posted 9 years ago
“great product”
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Posted 9 years ago
“This item was easy to install, and works perfectly. It is small enough to fit easily under the sink in a bathroom vanity cabinet. My only (small) complaint is that it is noisier than I would like: but since it is in a guest bathroom that will not see constant use, I can deal with it.”
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Posted 9 years ago