DeWalt Transfer Pump Kit

Why I reached for a cordless transfer pump

I spend an unreasonable amount of time draining water heaters, flushing small hydronic loops, and moving water from places it doesn’t belong to where it does. Dragging cords, finding an outlet, and worrying about GFCI trips is the part I like least. That’s what pushed me to try the DeWalt 20V transfer pump. After several weeks of jobsite use, it’s become the tool I toss in the truck for quick-hit tasks where portability and speed matter more than all-day duty cycles.

Setup, ergonomics, and build

The pump is compact and easy to carry at under 9 lb, and it sits planted thanks to rubber feet that cut down on vibration walk. The LED-embedded power switch is simple but helpful—you can glance at the pump and know it’s on, even in a noisy mechanical room where you might not hear it over other equipment. The housing feels like the typical DeWalt jobsite plastic: not indestructible, but it’s shrugged off a couple of trunk tumbles and one splashy basement mishap without complaint.

DeWalt includes a 5.0Ah 20V Max battery and a charger in the kit, which means you can actually put the tool to work right away. It also accepts larger FlexVolt packs, which I recommend if you plan to push higher head heights or run for longer stretches. It’s “Tool Connect Tag Ready,” so if you’re managing a fleet of tools, you can add a Tag and keep tabs on it—useful in shared vans or larger facilities.

Priming and ease of use

Self-priming is the headliner here, and the pump mostly lives up to it. With wetted hoses, it grabbed prime quickly—typically within a few seconds—and kept it unless I kinked a hose or starved the inlet. Running dry briefly didn’t immediately spell trouble, but I avoided it, as you should with any small transfer pump. As with all pumps, the shorter and straighter your hose runs, the happier the pump will be. Keep the inlet as low and as unrestrictive as possible, and you’ll get the best performance.

One small note: the switch placement and battery latch are glove-friendly, and swapping packs mid-job is quick. There’s no fancy interface—just on/off—which I prefer for a tool like this.

Performance in the field

DeWalt advertises up to 10 GPM in ideal conditions with tap water. In real-world use, my numbers varied with head height and hose setup:

• Draining a garden-level water heater with minimal lift and short hose runs: roughly 8–9 GPM by bucket-and-timer.
• Moving water up one story (about 10–12 ft of head) through a moderate run of hose: 6–7 GPM.
• Pushing to higher head scenarios closer to 20–25 ft: 4–5 GPM, which tracks with DeWalt’s claim of ~4.5 GPM at 45 ft equivalent head.

Those are respectable numbers for a compact battery pump. It’s not going to outrun a big corded utility pump on wide-open flow, but for quick transfers, draining small tanks, or flushing lines, it’s fast enough that I don’t miss the cord.

Noise is typical for a brushed pump motor: a steady whirr with a bit of mechanical chatter at higher head. I could comfortably work next to it, but in echoey rooms you’ll notice it.

Battery life and runtime

Runtime is the trade-off with any cordless pump, and that’s true here. On the included 5.0Ah pack, I consistently got a couple hundred gallons per charge when pushing against moderate head with reasonable hose routing. Under easier conditions (low head, short hoses), I could approach DeWalt’s “several hundred gallons per charge” claim. At maximum head or if you’re constricting the outlet with small-diameter hose, expect noticeably shorter runtimes.

A few practical tips that made a difference for me:
- Use the largest reasonable hose diameter to lower system resistance.
- Keep hose runs short and avoid sharp bends and restrictive fittings.
- If you know you’ll be pumping for a while, step up to a 9Ah or 12Ah FlexVolt pack. The larger packs materially extend runtime and hold voltage better under load.
- Have a second battery on the charger; swapping packs is quicker than moving and setting up a corded alternative partway through a job.

Compatible fluids and limitations

The pump is rated for water and water/propylene glycol mixes up to 40% glycol, which covers most hydronic flushing and winterization tasks. That’s a meaningful advantage over basic utility pumps that aren’t glycol-friendly. It’s not for fuel, solvents, or fluids outside the stated compatibility—stick to the manual on that point.

Maximum lift is listed up to 25 ft, which is consistent with my experience. If you’re routinely working at that limit, understand that flow will be modest and runtime will suffer. For high head, continuous pumping, a corded solution is still more efficient.

Maintenance and durability

It’s a brushed motor, and you can feel that in the slightly higher noise and slightly lower efficiency versus a brushless design. That said, I didn’t run into overheating or cutouts in normal use. Letting the pump rest between long cycles and keeping the inlet well supplied with water kept it happy. The rubber feet and overall footprint help with stability; I never had it tip or wander when set on a reasonably flat surface.

As with any transfer pump, the biggest maintenance is protecting it from freezing with water inside, especially after glycol work where a rinse can be tricky. I made a habit of letting it run a few seconds with the outlet hose disconnected (in a safe place) to clear residual water, then cracking the fittings to drain the last bit.

Value of the kit

The inclusion of a 5.0Ah battery and charger is important. If you’re already on the DeWalt 20V platform, this pump fits right in and your larger packs will give it longer legs. If you’re not, the kit still makes sense because it’s ready to work out of the box—no separate purchases before your first job.

Warranty coverage is straightforward, and the tool’s size and weight make it easy to store in a milk crate alongside hoses and adapters. There aren’t extra modes, speed controls, or app gimmicks—just a practical, portable pump.

Who it’s for (and who it isn’t)

• Plumbers and HVAC techs: Great for draining small tanks, flushing zones, and moving water/glycol in tight spaces where a cord is a hassle.
• Maintenance teams and property managers: A reliable grab-and-go option for minor flooding and transfer tasks without hunting for power.
• DIYers with occasional needs: Worth it if you already use DeWalt 20V tools or if portability is a priority.

If you need to move thousands of gallons continuously, or you often pump at high head for long durations, a corded pump will be more economical and less battery-dependent.

Pros and cons

Pros:
- Truly portable, self-priming, and quick to deploy
- Solid real-world flow for its size; handles water and 40% propylene glycol
- Stable footprint with rubber feet; simple, visible power switch
- Accepts 20V MAX and FlexVolt packs; kit includes battery and charger
- Tool Connect Tag Ready for asset tracking

Cons:
- Runtime on a 5.0Ah pack can be short under high head or restrictive plumbing
- Brushed motor means more noise and slightly less efficiency than brushless options
- No speed control or advanced features (a pro for simplicity, a con if you want fine tuning)

Recommendation

I recommend the DeWalt 20V transfer pump to tradespeople and maintenance pros who value speed and portability over all-day continuous duty. It’s a genuinely useful jobsite tool: fast to set up, easy to prime, and strong enough to handle most small-to-medium transfer tasks, including water/glycol work. Be realistic about runtime—understand that higher head and restrictive hoses will shorten battery life—and plan to carry a second battery or step up to a larger FlexVolt pack if you’ll be pumping for extended periods. If your use case involves long, continuous pumping or the highest head pressures, a corded unit will serve you better. For everything else, this cordless pump earns its spot in the kit.