DeWalt 1/3 HP Stainless Steel / Cast Iron Submersible Sump Pump

I swapped out an aging pedestal pump for this DeWalt 1/3 HP sump pump during a wet stretch, so it didn’t get the luxury of a gentle shakedown. It went straight into daily duty, cycling every few minutes at times. The first impression was how substantial it feels for a 1/3 HP unit. The stainless-steel housing and cast-iron base give it real mass and stability in the pit, and the overall footprint fits a standard 18-inch basin without crowding the float or discharge.

The motor is an oil‑cooled, hermetically sealed, continuous-duty design rated at 6.5 amps. That matters for two reasons: it tolerates frequent cycling without heating up, and it’s built to run for extended periods during big storms. There’s also a thermal overload with auto‑reset, which I hope never trips but is good insurance if a discharge line freezes or a check valve sticks.

Underneath, the cast-iron impeller is a nice step up from the plastic parts you often find in this class. It’s designed to pass 1/2-inch solids, which in the real world means small gravel and organic debris won’t immediately jam it. I pulled the pump after a week to check for scuffing and found only a bit of silt—no galled surfaces, no unusual wear.

Installation was straightforward. The pump ships with a 2-inch female discharge and includes an adapter to 1-1/2-inch, which is what most residential plumbing uses. If you already have 1-1/2-inch PVC, the adapter threads on cleanly and seals well with thread tape and a light pipe dope. If you have the option to run 2-inch all the way out, you’ll squeeze a bit more flow and reduce head loss, but retrofits will be perfectly fine on 1-1/2-inch.

One thing to plan for: it doesn’t include a check valve. You’ll want a quality, quiet check valve rated for vertical installation. Put it as close to the pump as practical, include a union for easy service, and verify the arrow points away from the pump.

DeWalt uses a vertical float switch with a piggyback plug. I prefer this style over tethered floats for narrow pits—there’s less to snag against the basin wall or the discharge. The piggyback plug makes testing a breeze: unplug the switch and plug the pump directly into the outlet for manual operation. The switch is factory-rated to millions of cycles, and the action on mine is crisp. With the pit half full, it kicked on decisively and shut off cleanly with only a brief spin-down.

Performance-wise, this pump moves water. Rated at 75 GPM (4500 GPH) at zero head, it’s still strong where it counts: 63 GPM at 10 feet and 56 GPM at 15 feet. In my setup—about 9 feet of vertical lift and 1-1/2-inch discharge—the pit cleared quickly without the motor sounding strained. The cycle times shortened compared with the pedestal pump it replaced, and the basement floor stayed noticeably drier around the pit during heavy inflow. At 20 feet of head the spec drops to 27 GPM (1620 GPH), so if you’re pushing higher lifts or very long runs, consider stepping up to a higher horsepower version. For typical basements, 1/3 HP here is more than adequate.

Noise is pleasantly subdued. You’ll hear the check valve more than the motor if you’re using a basic flapper valve, so if sound matters, invest in a spring-loaded, “quiet” check valve. The pump itself hums rather than whines, and the cast-iron base dampens vibration well.

A couple of practical notes from the install and early use:
- Relief/weep hole: Like many submersibles, this pump needs an air relief hole in the discharge line between the pump and the check valve to prevent airlock. If you don’t already have one, drill a small hole (typically 3/16 inch—confirm your manufacturer guidance) and angle it back into the pit. If you place it too high or angle it toward the basin wall, you’ll get a surprising spray and backsplash during the initial seconds of a cycle. Aim it downward and, if possible, below the typical waterline. Keep it clear; a clogged hole can cause airlock and a no‑pump condition.
- Electrical: The 10-foot cord is adequate for most pits, but plan your receptacle location accordingly and avoid extension cords. Use a dedicated circuit and follow local code for GFCI requirements in basements.
- Handling: The integral carry handle is simple but appreciated; the pump weighs about 24 pounds and you’ll need to fish it in and out a few times for dry fits.

Over the first weeks, the DeWalt settled into a consistent rhythm with no nuisance short-cycling. The vertical float’s compact travel is a good match for narrower pits, and it’s less likely to hang up on discharge fittings or pit walls. I made a point to test manual operation by bypassing the switch at the piggyback plug; the pump primed immediately and ran smoothly, a good sign that the impeller isn’t cavitating.

Durability is where the design really earns its keep. Stainless around the motor housing resists corrosion from damp basements and mineral-rich water, while the cast iron adds heft and stability. The shaft is stainless, and the carbon/ceramic/stainless seal is a proven recipe for long life in this kind of service. The 10‑year limited warranty is unusually strong in this category, and while warranties don’t pump water, they do reflect confidence in the build.

What I’d change:
- Include a check valve. Most installs need a new one anyway, and bundling a quiet valve would make the out-of-the-box experience cleaner.
- Offer a longer cord option. In some layouts, 10 feet is just shy of ideal.
- Provide clearer guidance or a small deflector for the relief hole. Homeowners new to submersibles are often surprised by the brief spray. A tiny angled nozzle or a pre-drilled, directional insert would help.

Maintenance is the usual sump pump routine. Pull the pump seasonally (or at least annually), flush silt, and make sure the float moves freely. Test the piggyback switch by lifting the float manually and by using the bypass. Check the check valve for slam or seep. While you’re at it, consider a sealed pit cover; it cuts down on humidity, controls any mist from the relief hole, and quiets the system further. If you rely heavily on your sump, pairing this pump with a battery backup unit is cheap insurance.

Who it’s for: homeowners with a typical basement pit, moderate head height (up to ~15 feet), and frequent cycling during wet seasons. If you’ve struggled with tethered floats snagging or pedestal pumps keeping you up at night, this compact vertical-float submersible is a meaningful upgrade. If you have unusually high lift or a very long run to daylight, look at a 1/2 HP or 1 HP in the same family.

Bottom line: I recommend this DeWalt sump pump. It’s a thoughtfully built, heavy-duty 1/3 HP unit that balances strong performance with quiet, low‑fuss operation. The stainless/cast-iron construction, cast-iron impeller, and continuous-duty motor inspire confidence, and the vertical float with piggyback plug makes installation and testing straightforward. You’ll need to supply your own check valve and pay attention to the relief hole placement, but those are small asks for a pump that clears water quickly and feels engineered to last. The long warranty is the clincher for me; paired with sensible maintenance, this is the kind of set‑and‑forget pump I want guarding a basement through storm season.