DEWALT DXPW4240 Pressure Washer Review

By Robert Robillard on Tool Reviews

DEWALT DXPW4240 4,200 PSI 4.0 GPM Gas Pressure Washer with Honda EngineDEWALT DXPW4240 Pressure Washer


At A Concord we try to bring all of the tools we test to the job site.  So you’re probably asking the question what in the world will carpenters do with a pressure washer?

Good question.  While we planned on giving this unit to our painting contractor to test and use we also have several property maintenance  clients that have hired us to manage their property.


We decided to use the DEWALT DXPW4240 pressure washer to clean their blue stone patio and pool deck.  Every year the blue stone discolors due to leaf tannins form the fallen leaves and mildew and we normally do this each year with a stiff brush and a sweeper nozzle on a hose. trust me it takes a long time to do!


A pressure washer is a high pressure sprayer that can be used to remove loose paint, mold, grime, dust, mud, and dirt from surfaces and objects. The volume of a pressure washer is expressed in either gallons per minute.


DEWALT sent us this unit to review and I must admit I was not prepared for my first impression.  I had figured the DEWALT was going to be a typical pressure washer with a yellow tag stuck on it and everyone would say ohhhh it’s DEWALT it must be nice.

When I took this unit out of the box and assembled it I remember thinking how well made and sturdy it appeared.   The frame is a tubular steel, 12 gauge, welded construction combination with a .63″ axle and 13 inch, double sealed pneumatic tires.

The engine is a gas powered Honda GX390 commercial series OHV engine with engine oil alert and equipped with a comet pump.   I’ve had nothing but stellar luck with Honda motors, they are well made and have a proven track record.

IDEWALT DXPW4240 Pressure Washer Review

Adding oil to the unit at set up was annoying as I had to use a funnel.  I’d love to see engineers make maintenance for tool users easier and faster.

The pressure washer offers 5 quick connect nozzles tips in 0, 15, 25, 40 degree, has a detergent siphoning tube, on-board nozzle gun, hose and nozzle storage.-13”

The DEWALT DXPW4240 has a replaceable Comet pump which operates at 4200 PSI / 4.0 GPM and is clearly not a DIY tool or toy.  This unit is a real deal professional tool.


  • GX390 commercial grade motor
  • Overhead valve design –more efficient
  • Oil Alert System – shuts down unit when low on oil
  • Cast iron cylinder liner – durabilityDEWALT DXPW4240 Pressure Washer


  • Triplex plunger pump – industrial grade
  • Ceramic pistons
  • Forged brass head – durable
  • Thermal relief valve protects pump from overheating
  • Oil level window – easy to visually check oil level
  • Quick hose connection disconnects


Five different types of nozzles are offered, Spray Patterns 0°. 15°, 25°, 40°, & Soap dispensing.  Each nozzle is useful for different cleaning DEWALT DXPW4240 Pressure Washerapplications. The difference in nozzles is with the water jet.  Some eject water in a triangular plane (fan pattern), while others emit a thin jet of water, which spirals around rapidly (cone pattern)  All of the nozzles connect to the spray want with a fast and easy disconnect coupling.


Let me start by saying that the DWPW4240 is a sturdy, professional grade tool with a ton of water pressure.  Long term use at full pressure use actually tired me out – it was like trying to hold onto a fire hose!

We used it on a pool deck, driveway, and a 1/4 mile of blue-stone walkways and were amazed at how fast we were able to get the job done.  Not only was it way faster, it also did a better job at cleaning than hand cleaning and with no harmful chemicals!DEWALT DXPW4240 Pressure Washer

We used this unit on a large property and had to connect several hoses to it to get it to where we needed it to be.   The manual says to extend the water inlet hose as opposed to  extending spray wand hose.    We did both and found that if the spray wand hose is extended too far a drop in pressure is noticeable.  Follow the  manual!

The unit is easy to start, move around and operate.  The on-board storage for the spray wand and hose is a nice touch .  We used one way ties to secure the nozzle cleaning tool to the unit so it would not be lost.

One annoying thing with the spray wand holder is it does not work well when transporting the unit across grass or bumpy terrain.  The spray either falls out or it slides forward and digs into the ground.  I’d like to see DEWALT add a wand rest at the lower end to prevent this from happening – easy to do!

Another nice feature is the start up procedure and operating instructions are printed on a weather proof label and afixed to the unit for quick reference – a great feature to remind employees to operate the  tool properly.

FEATURES:DEWALT DXPW4240 Pressure Washer

  • HONDA GX Commercial Series Engine Starts Easy, Runs Smoothly, and Delivers High Output
  • Direct Drive Engine & Pump for Streamlined Power Transmission from Engine to Pump
  • Triplex Pump Design with Ceramic Pistons and Thermal Relief Valve.
  • Adjustable Unload-er system for added control and versatility.
  • Welded Construction, 1-1/4″ Tubular Steel with Steel Engine Plate and Solid Steel 5/8″ Axle
  • 3/8″ x 50′ Non-marring Hose with Quick Connectors for No Tools Assembly
  • 5 Quick Connect nozzles (0°. 15°, 25°, 40°, & Soap) make swiching applications easy and fast!
  • Downstream Detergent Injection SystemDEWALT DXPW4240 Pressure Washer


  • Water Pressure 4200PSI
  • Flow Rate 4.0GPM
  • Engine Mfgr. HONDA®
  • Pump Brand FNA
  • Wheels 13″ Premium Pneumatic
  • Pump/Hose Quick Connector Yes
  • Hose 50′ x 3/8″ High Pressure Hose
  • Hose/Gun Quick Connector Easy Connectors
  • Wand Type Steel Wand with Quick ConnectDEWALT DXPW4240 Pressure Washer
  • Spray Patterns 0°. 15°, 25°, 40°, & Soap
  • Engine Orientation Horizontal
  • Frame 1-1/4″ Welded Steel
  • Frame Tube Style Tubular Steel
  • Frame Handle Style Tublar Steel
  • Accessory Storage On Board
  • Gun 2 piece


I was extremely impressed at the amount of cleaning power this unit has.  The unit is PRO grade all the way and has adequate pressure to clean everything and anything. DEWALT DXPW4240 Pressure Washer

The motor started on the second pull and idles relatively quiet.

As a carpenter and contractor the uses for a pressure washer are endless and considering how much time and labor expense it saved me on the blue-stone walk project it’s a no brain-er to have one.    Time is money and time saved is money earned!

After seeing how well the DWPW4240 works we’ve started discussing other time saving projects to use it on.  Recommended. 


The DEWALT DXPW4240 pressure washer can be purchased for approximately $ 978.00 online here:  DEWALT DWPW4240 Pressure Washer  as well as at

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About the author

Robert Robillard

Carpenter / Remodeler / Editor

Rob Robillard is “The Concord Carpenter” Rob is a builder, general contractor, carpenter, woodworker, and editor of Concord Carpenter and ToolBoxBuzz As a General Contractor and carpenter, Rob owns and operates Concord Carpenter LLC. A full-service remodeling and construction company. Rob is a recognized leader in home building best practices and a source for how-to information for building professionals. On this website, Rob covers all aspects of home construction, building science, home improvement, woodworking, remodeling, and some of the best product and tool reviews. Rob is in charge of our Tool and Product Review series - Concord Carpenter Videos where we post all of our tool reviews and video tutorials. Rob approaches remodeling and building construction with a pragmatic and problem-solving approach. He enjoys using his knowledge and experience to help and educate building professionals as well as DIYers on best practices in the construction and remodeling industry. He's a strong advocate for "raising the bar" in the construction trades and promoting the trades to youth. #BeAMentor #Green2Great Craftsmanship, quality, and pride guide his journey on this channel The Concord Carpenter's motto: "Well done is better than well said!" : Read more about Rob

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