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
“Helpful little pump for a sink drainage line going slightly upward. Works well since a couple of days now, was easy to install and solved a big problem to our satisfaction. Only disadvantage: It isn't very quiet.”
Helpful Report
Posted 4 years ago
“I hired a plumber to install for my wet bar and dishwasher. It works as directed. Only issue now if GFCi trips. Will keep researching why. Might be something on my end.Might put a rubber man under to dampen noise and a water detector for insurance sake cause I don't trust anything water in a basement.”
Helpful Report
Posted 4 years ago
“Outstanding piece of equipment. Does exactly what it claims.”
Helpful Report
Posted 4 years ago
“Excellent help from the plumbingsupplyandmore team. A new one was shipped and it is working as it should. Thank you for the help.”
Helpful Report
Posted 4 years ago
“It is so quiet while in use that you barely hear it working. We are quite pleased with the product and it's function!”
Helpful Report
Posted 5 years ago
“We added a full bathroom to our basement because our kids play sports and have sleepovers almost every weekend. We wanted the convenience of keeping everything downstairs including muddy athletes walking into the basement and showering before entering the main part of the house.While we could have the shower and sink lines to the Saniflo macerater we use for the toilet we decided to purchase the grey water pump for the shower and the sink for 2 reasons:1) It would make the piping easier to connect to another pump in our configuration.2) The Grey Water pump is super quiet and we wouldn't have to hear the larger pump run more frequently.It's been well over 2 years and both Saniflo pumps have worked great without any issues. Very happy with the added convenience of a full bath in the basement and the Saniflo product line.*The only maintenance I do is to run the descaler through the pumps every 6 months. That is a very simple process that takes little time.”
Helpful Report
Posted 5 years ago
“Recomendado”
Helpful Report
Posted 5 years ago
“Had a situation where a drain in a house slab was in the middle of a room expansion. Use this product to relocate shower/sink drain to a much more convenient location for a better room design layout.”
Helpful Report
Posted 5 years ago