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

A stout, quiet primary pump that’s easy to live with

A sump pump you forget about is the best kind. After swapping in DeWalt’s 1/3 HP sump pump during a wet stretch, it quickly settled into the background—moving a lot of water without drama, humming quietly, and cycling predictably. The build quality is immediately reassuring: stainless steel body, epoxy‑coated cast iron base and volute, and a cast iron impeller. At roughly 25 pounds, it sits planted in the pit and doesn’t buzz around when it kicks on.

I tested it as a primary pump in a standard 18-inch pit with a roughly 10-foot vertical lift to the discharge. If you’re replacing an older pedestal pump or a lightweight thermoplastic unit, the upgrade in fit and finish is obvious.

Setup and first impressions

Installation is straightforward. The pump ships with a 2-inch FNPT discharge and includes a 1‑1/2 inch adapter; I reused my existing 1‑1/2 inch PVC stack and slipped the adapter on with thread sealant. The kit’s full‑flow check valve is a nice inclusion. It’s a simple, serviceable in‑line design that added minimal restriction and kept water hammer to a dull thud. If you’re replacing an older flapper valve, you’ll likely notice fewer clunks on shutoff.

The vertical float switch is piggy‑backed: the float plugs into the outlet, the pump plugs into the float. That means you can bypass the float for manual operation during testing or servicing without rewiring anything. The float’s travel is short by design—great for narrow pits. Before buttoning up, I made sure the float had a clear path with no cords or pipe rubbing against it.

One setup note that matters: this pump, like many submersibles, needs an air‑bleed (weep) hole in the discharge line to prevent airlock. I drilled a 3/16-inch hole about 6 inches above the pump outlet and angled it back into the pit. That prevents the pump from cavitating on startup. The tradeoff is a thin, pressurized stream while the pump runs. Angling the hole down and using a pit lid keeps incidental spray contained. It’s worth adding “clean the weep hole” to seasonal maintenance, especially in hard water areas.

Power is a standard 120V plug with a 10-foot cord. I ran it to a dedicated GFCI receptacle—no extension cords per guidelines.

Performance under load

With roughly 10 feet of head and two swept 90s on the way out, the DeWalt pump cleared my 18-inch pit in about 12–15 seconds per cycle, which lines up with the published 63 GPM at 10 feet. The PSC motor spins up smoothly and holds a steady tone—no chatter, no noticeable resonance in the discharge stack. Moving to a 2-inch riser would eke out more performance, but on a 1‑1/2 inch run the pump still moves serious water for a 1/3 HP unit.

The cast iron impeller and 1/2-inch solids rating inspire confidence. I purposely didn’t over‑sanitize the pit before the swap; there was the usual grit, organic bits, and a stray zip‑tie fragment that had fallen in at some point. The pump shrugged it off. If your pit sees silt, I’d still recommend a basin liner or a quick shop‑vac once or twice a year, but this impeller design is less fussy than many.

Thermal behavior was uneventful. After extended cycling during a storm, the housing was warm but never concerningly hot. The motor is thermally protected and uses copper windings with dual O‑ring seals—exactly what you want for frequent, short runs.

Noise and vibration

It’s quiet. You’ll hear a low, even hum and the rush of water in the pipe more than the motor itself. Compared to a pedestal pump, the overall sound profile is lower and less mechanical. The included check valve smooths the shutoff clunk. The only odd sound in my setup was a faint hiss from the weep hole when the pump ran; this went away once I covered the pit.

If noise is a big concern in a finished basement, a tight‑fitting pit lid and flexible couplers at the valve can knock a few more decibels off without sacrificing serviceability.

Float switch behavior

Vertical floats are inherently less prone to getting hung up than tethered floats, and this one is no exception. It cycled reliably and consistently at shallow and high water levels. The piggy‑back plug makes troubleshooting simple: unplug the pump from the float, plug it directly into the outlet, and you can verify motor operation independent of the switch. DeWalt rates the switch for millions of cycles; I can’t validate the number, but the action feels crisp and the housing is stout.

As with any float, give it clearance on all sides. In small pits with lots of fittings, the most common cause of “mystery failures” is a float catching on a pipe or cord.

What I like

• Durable build. Stainless shell and cast iron where it counts. The weight keeps it stable.
• Strong flow for 1/3 HP. At typical residential head, it punches above its weight.
• Quiet operation. Minimal vibration transmitted to the piping with a proper check valve.
• Sensible kit. The included adapter and full‑flow check valve reduce hardware runs.
• Service-friendly. Piggy‑back float and standard pipe sizes make future maintenance easy.
• Warranty. A 10‑year limited warranty is unusually long for a primary pump class.

Where it could be better

• Weep hole spray. Air‑bleed is necessary to avoid airlock, but expect a small stream. Aim it down and use a lid to keep things tidy, and plan to clean the hole periodically.
• Cord length. Ten feet is fine for most pits, but basements with distant outlets may need an electrician to add a receptacle. Avoid extensions.
• Size and weight. The heft is a plus in the pit but less fun during install if you’re reaching past tight joists or deep basins.
• Headroom. Max lift is 25 feet; if your run is unusually tall or restrictive, consider the 1/2 HP or 1 HP versions for more headroom.

Maintenance notes

• Keep the pit clean enough that the float can swing freely.
• Inspect and clean the weep hole every few months; mineral buildup can restrict it.
• Test the pump and float before major storm seasons by lifting the float manually.
• Inspect the check valve annually; replace if you start to hear slamming on shutoff.
• Consider a battery backup pump and a water alarm. Even a robust primary pump can be defeated by a tripped breaker or a power outage.

Who it’s for

Homeowners with a standard 18–24 inch pit, a vertical lift under 15 feet, and frequent cycling will appreciate this pump’s mix of performance and quiet operation. If you’re replacing a pedestal pump to get noise down, or you want a sturdier primary pump capable of handling grit without fuss, this model makes a lot of sense. If your discharge height is unusual or you’re dealing with a high‑volume aquifer, jump up in horsepower—or run this as your primary with a higher‑capacity secondary.

The bottom line

The DeWalt sump pump nails the fundamentals: durable materials, strong performance for its class, consistent float operation, and a kit that includes the bits you actually need. After installing and running it through both daily cycles and storm surges, it proved to be a set‑and‑forget primary pump—quiet, capable, and confidence‑inspiring. Plan for the small realities of submersible ownership (a weep hole to manage, occasional cleaning), and it rewards you with years of low‑drama service.

Recommendation: I recommend this pump as a primary unit for most residential basements. It combines solid construction, thoughtful design, and real‑world performance that matches the spec sheet, with the added reassurance of a long warranty. If you size it correctly for your head and flow, install the weep hole carefully, and pair it with a backup strategy, it’s an excellent, low‑maintenance choice.