Milwaukee M18 Transfer Pump Review

Milwaukee M18 Transfer Pump
PTR Review
  • Pro Review 9.0

At $179, it's an easy decision to recommend the Milwaukee M18 Transfer Pump. If you need to move water out of or through something, call on this pump and the work is as good as done - without an extension cord!

Overall Score 9.0 (out of 10)

Some of us have grandparents that can recall fetching water from a well with a hand pump. They could scarcely imagine an electric pump for moving water from place to place. Today it’s common in plumbing maintenance and repair to use such a pump to accomplish the work. As usual, technology marches on and now it has presented us with the Milwaukee M18 Transfer Pump – a cordless way to move water.

Even if you’re not a professional plumber, you’ve probably come across the need for a transfer pump. They drain water heaters for replacement or maintenance, help remove water from basements, remove water from tubs or sinks that are backed up, and much more. Even boats use a transfer pump (bilge pump) to remove excess water.

There are several classes of transfer pumps from small electric models that are rated for 100 gallons per hour all the way to monstrous gas models that can move hundreds of gallons per minute. For plumbing, we stay on the smaller side for most jobs and flow rates tend to be closer to 300 gallons per hour for the kind of pump I normally turn to.

I’ve been really impressed with some of Milwaukee’s new plumbing tools such as the Aluminum Pipe Wrench and Cheater Pipe Wrench, so I expect good things from the new pump.

The main task I have in mind for the Milwaukee M18 Transfer Pump is water heater maintenance.

First Impressions

This self-priming pump is a compact 13.2-inches long x 6-inches tall x 5.75-inches wide, including a convenient handle. It’s pretty lightweight coming in at just under 8 pounds.

The battery compartment opens to accommodate the M18 battery which Milwaukee claims can pump up to 144 gallons on a 3.0 amp hour battery at a rate of 8 gallons per minute or around 480 per hour. That’s a significant increase from the 5 gallons per minute I normally get. The pump also accepts larger M18 packs like the new 9.0 amp hour battery that packs 162 total watt-hours of capacity. Mathematically, the larger battery will get you 432 gallons of water transfer.

Milwaukee M18 Transfer Pump 01

The Milwaukee M18 Transfer Pump is capable of providing lift suction up to 18 feet. If you’re pumping from a level source or your source is above the pump, you can discharge up to 75 feet of head. That’s in a perfect setup. If you have to pull from a lower source, your available pressure for head height will decrease accordingly.

A window gives a clear view to the impeller. Just four screws hold the impeller housing in place, so it looks easy to replace when the time comes. There’s also an auto shutoff for protection.

Milwaukee M18 Transfer Pump 03

Pump It Up

For this review, I flushed out several tankless water heaters – including my own – with a vinegar solution. Regular flushing of tankless water heaters isn’t a code issue but rather a warranty requirement to prevent the scaling buildup and ensure proper function. With tankless heaters becoming more prevalent thanks to the energy savings, the demand to keep them running properly has gone up as well.

Milwaukee M18 Transfer Pump 04

It’s important to point out that this is not an effluent pump, that is, it’s meant only for water, groundwater, and some brown water from copper pipes. It’s perfect for draining a toilet for maintenance, pumping out a hole containing a broken pipe, performing a flush like I did for the review, or any other time when moving relatively clean water is needed.

Often a corded effluent pump is used for this work, but Milwaukee’s is a dedicated pump only used for much cleaner water and not actually rated for sewage. I wouldn’t want to use an effluent pump that had run sewage to flush my tankless water heater anyway. The Milwaukee M18 Transfer Pump also shouldn’t run blackwater or combustibles like gasoline.

Pro Tip: Turn the power off to the tankless water heater so it’s not firing up while you’re flushing it.

More Features

This pump is pretty straightforward: it has a 3/4-inch inlet, a 3/4-inch outlet, and a power button. Connecting hoses the inlet and outlet is simple (following the white arrow indicating flow) and, with the press of the button, the pump fires up and effortlessly moves the solution through the unit. It’s fairly quiet, and you can see the impeller work through the viewing window.

Milwaukee M18 Transfer Pump 06

Several people have asked about being able to vary the water flow with this unit, and you can’t. For most plumbing jobs, the flow rate is great where it is, but other users that want a slower rate will want to note that.

One feature that stands out during use is the auto shutoff capability. Once the system detects that no water is moving through the impeller, it shuts down. This prevents heat build-up and damage. That’s pretty nice if you want to start a transfer on one part of the job and walk away to get another underway.

The Bottom Line

Many compelling reasons will drive Pro plumbers to seriously consider the M18 Transfer Pump, especially ones already on the Milwaukee RedLithium battery platform. Standing above the rest have to be the cordless convenience, solid flow rate, excellent run time, and self-priming features.

Milwaukee M18 Transfer Pump 02

But there’s more. Quiet and simple operation along with easy access to the impeller and auto-shutoff wrap this up in a package that has become my go-to transfer pump whenever I need one.

Milwaukee has a knack for making even complex tools intuitive.  It’s refreshing to have tools that simply work as you need them to. I needed a compact, convenient pump for moving water and they’ve created one. What’s even better – I don’t have to run an extension cord or find an outlet. The Milwaukee M18 Transfer Pump is another win for the company.

At $179, it’s an easy decision to recommend the Milwaukee M18 Transfer Pump. If you need to move water out of or through something, call on this pump and the work is as good as done – without an extension cord!

Milwaukee M18 Transfer Pump Key Features

  • Self-Priming: connect and go
  • Pumps up to 480 gallons per hour
  • Lift: Up to 18 feet
  • Head Height: Up to 75 feet
  • Inlet connection: 3/4-inch brass
  • Outlet connection: 3/4-inch brass

Milwaukee M18 Transfer Pump Specifications

  • Model: Milwaukee 2771-21 (kit), Milwaukee 2771-20 (bare tool)
  • Power Source: Milwaukee RedLithium 18V battery
  • Length: 13.2 inches
  • Weight: 7.9 pounds
  • Height: 6.0 inches
  • Width: 5.75 inches
  • Tool Warranty: 5 years
  • Price: $199 (bare), $319 (kit with 3.0 amp hour battery)

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Victor Mitchell

Used this to clean out my cistern when it got low. Amazing. Pumped out 500 gallons. Only down side is the the 12amp hour doesn’t fit.


Hi, how is the water pressure? I am actually thinking of using this to transfer water from a rain catcher container to 1. flush my boat engine with fresh water and 2. wash my boat

its at a storage facility and they dont allow use of their water or power so i am looking for a cordless option.

Would love your thoughts, please comment.x