Whirlpool WPSUM33 1/3 HP Submersible Sump Pump

Whirlpool WPSUM33 -- brand-name reliability at accessible pricing

The Whirlpool WPSUM33 delivers 3,000 GPH from a 1/3 HP motor with a cast iron volute over a thermoplastic outer body. The cast iron water contact surfaces resist the abrasive wear from pit sediment that shortens the service life of all-plastic impeller-and-volute designs. The vertical float switch activates at 6.5 inches and shuts off at 2.5 inches -- a 4-inch operating range that limits cycling frequency and protects the motor from the thermal stress of rapid on/off cycling.

Retail network advantage

The WPSUM33 is stocked at Lowe\'s and Home Depot nationwide -- an important practical consideration for sump pump replacement, which most homeowners perform during or immediately after an active flooding event. Ordering from a specialty pump distributor with a 2 to 5 day shipping window is not a realistic option when water is entering the basement now. The Whirlpool retail network advantage means a replacement pump is available same-day in virtually any US metro area.

Performance context: WPSUM33 vs. Zoeller M53

At comparable 1/3 HP specifications, the Whirlpool WPSUM33 delivers 3,000 GPH vs. 5,400 GPH at 0 head for the Zoeller M53 (Zoeller uses a more aggressive impeller design). At 10-foot head, the gap narrows: WPSUM33 at approximately 2,100 GPH vs. Zoeller M53 at 4,080 GPH. For basements with moderate inflow (under 2,000 GPH peak), both pumps are adequate. For higher inflow, the Zoeller M53 or Whirlpool WPSUM50 is the appropriate upgrade. The WPSUM33 provides solid Whirlpool brand value in the moderate-performance tier.