Head-to-Head Comparison · 1/3 HP Class

Liberty Pumps 257 1/3 HP Cast Iron Sump Pump vs. Liberty Pumps S38 1/3 HP All Stainless Steel Sump Pump (20ft)

Engineering comparison between the Liberty Pumps 257 1/3 HP Cast Iron Sump Pump and Liberty Pumps S38 1/3 HP All Stainless Steel Sump Pump (20ft). Flow curves, switch durability, and technical verdict.

Liberty Pumps

257 1/3 HP Cast Iron Sump Pump

LIBERTY PUMPS 257 Technical Specification Schematic
$264SupplyHouse listed price · observed Sep 30, 2026
Liberty Pumps

S38 1/3 HP All Stainless Steel Sump Pump (20ft)

LIBERTY PUMPS S38-20FT Technical Specification Schematic
$319SupplyHouse listed price · observed Sep 30, 2026
The Technical Verdict

The Liberty Pumps 257 1/3 HP Cast Iron Sump Pump delivers 2,040 GPH at 10' head compared to 2,200 GPH for the Liberty Pumps S38 1/3 HP All Stainless Steel Sump Pump (20ft). If your basement requires maximum flow throughput, the Liberty Pumps holds the hydraulic advantage. For tight sump pits, compare the minimum basin clearances: 10" vs 10".

Specification Comparison Matrix

Specification Liberty Pumps 257 1/3 HP Cast Iron Sump Pump Liberty Pumps S38 1/3 HP All Stainless Steel Sump Pump (20ft) Advantage
Discharge Flow @ 10' Head 2,040 GPH 2,200 GPH Liberty Pumps +160 GPH
Shut-Off Head 21.0 ft 23.0 ft Liberty Pumps +2.0 ft
Switch Mechanism VMF Magnetically-Coupled Vertical Float VMF Magnetically Coupled Float Vertical Clearance
Housing Material Class 25 Cast Iron All 304 Stainless Steel Thermal Heat Sink
Minimum Basin Diameter 10" 10" Basin Fit
List Price $264.00 $319.00 Lower Initial Cost

Choose 257 1/3 HP Cast Iron Sump Pump If:

  • You require 2,040 GPH discharge capacity at standard 10' head.
  • Your installation prioritizes Class 25 Cast Iron for continuous motor heat dissipation.
  • You prefer the VMF Magnetically-Coupled Vertical Float switch mechanism.

Choose S38 1/3 HP All Stainless Steel Sump Pump (20ft) If:

  • You need 2,200 GPH flow capacity at 10' dynamic head.
  • Your sump pit accommodates a 10" clearance footprint.
  • You favor the VMF Magnetically Coupled Float actuation design.

Hydraulic Performance & Head Sizing

When operating at 10 feet of Total Dynamic Head, the Liberty Pumps 257 delivers 2,040 GPH versus 2,200 GPH for the Liberty Pumps S38-20FT. Pumping capacity curves indicate that both models handle standard residential foundation drainage effortlessly.

Switch Technology & Pit Clearance

The Liberty Pumps employs a VMF Magnetically-Coupled Vertical Float requiring a 10" pit, whereas the Liberty Pumps utilizes a VMF Magnetically Coupled Float suited for basins with at least 10" clearance. Ensuring your pit allows uninhibited float movement is essential to preventing switch hang-ups.