Search  for anything...
SIMPSON

SIMPSON Cleaning ALH4240 Aluminum Series 4200 PSI Gas Pressure Washer, 4.0 GPM, HONDA GX390 Engine, Includes Spray Gun and Extension Wand, 5 QC Nozzle Tips, 3/8-inch x 50-foot Monster Hose, (49 State)

    • Based on 1,473 reviews
Condition: New
Checking for product changes
$1,389.89 Why this price?
Save $109.11 was $1,499.00

Buy Now, Pay Later

As low as / mo
  • – Up to 36-month term if approved
  • – No impact on credit
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout. Payment plans are offered through our trusted finance partners Klarna, PayTomorrow, Affirm, Afterpay, Apple Pay, and PayPal. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

Availability: 18 left in stock
Fulfilled by Amazon
Arrives Tuesday, Mar 4
Order within 20 hours and 56 minutes
Available payment plans shown during checkout

Style: 4200 PSI Honda GX390


Features

  • Professional Performance: Easy-to-assemble and easy-to-start with its HONDA GX390 engine commercial series engine, the Aluminum Series power washer is great for contractors who specialize in deck cleaning, wood restoration, and all professional services
  • Power and Durability: A powerful, reliable, maintenance-free CAT Industrial triplex plunger pump delivers 4200 PSI at 4.0 GPM and includes thermal relief to prevent overheating
  • Sturdy and Portable: The aircraft grade aluminum platform with brushed extruded aluminum tubing offers durability and corrosion resistance; 13-inch premium pneumatic tires deliver ease of maneuverability across various terrain and uneven ground
  • Includes Quality Simpson Accessories: Monster 3/8-inch x 50-foot high-pressure hose is kink- and abrasion-resistant; 5 Quick connect nozzle tips: 0, 15, 25, 40 and Soap; 16-inch steel wand/lance; Professional spray gun with safety lock-out
  • Important Notes: 49-State Compliant; Pump/Hose Connection: Threaded M22 connection

Description

The SIMPSON Aluminum Series pressure washer 4200 PSI at 4. 0 GPM is great for construction, equipment upkeep, and facility and fleet maintenance cleaning. With a powerful HONDA GX390 engine, reliable CAT triplex pump, and ultra lightweight aircraft grade aluminum frame, this pressure washer is the optimum blend of maneuverability and performance. The ALH4240 also comes with a 50’ hose, ergonomic spray gun, and 5 Quick Connect nozzles. Designed to meet the rigorous demands of the cleaning professional, the SIMPSON Aluminum Series frame is crafted of 100% aircraft grade aluminum, making it lighter in weight than most steel frame pressure washer designs. Perfect for contractors who specialize in deck cleaning, wood restoration, paint preparation, graffiti removal and all other professional cleaning services. The SIMPSON Aluminum Series designed for optimum performance in the harshest environments. 10 Year Limited Frame Warranty, 5 Year Limited Pump Warranty, 3 Year Limited Engine Warranty. Includes: Pressure Washer, Hose, Gun, Wand, 5 Quick connect nozzle tips, Detergent siphon tube with filter, Engine Oil, Quick start set up guide, Owner's manual.

Brand: Simpson Cleaning


Power Source: Gasoline


Color: Red


Maximum Pressure: 4200 Pound per Square Inch


Item Weight: 124 Pounds


Hose Length: 50 Inches


Product Dimensions: 38"L x 23.5"W x 29"H


Tank Volume: 2.5 Gallons


Maximum Flow Rate: 4 Gallons Per Minute


Global Trade Identification Number: 45


Brand: Simpson Cleaning


Power Source: Gasoline


Color: Red


Maximum Pressure: 4200 Pound per Square Inch


Item Weight: 124 Pounds


Hose Length: 50 Inches


Product Dimensions: 38"L x 23.5"W x 29"H


Tank Volume: 2.5 Gallons


Maximum Flow Rate: 4 Gallons Per Minute


Global Trade Identification Number: 45


UPC: 879399001345


Item Weight: 124 pounds


Manufacturer: SIMPSON


Country of Origin: USA


Item model number: ALH4240


Is Discontinued By Manufacturer: No


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Mar 4

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • This thing is a beast!
Style: 4200 PSI Honda GX390
I read a LOT of reviews here on Amazon and other online resources before deciding to make such a sizable investment in this 4200 PSI/4.0 GPM machine. This is not my first pressure washer, but my third actually. Each time I upgraded in both PSI and gallons per minute. This is my first pressure washer that is categorized as commercial use. Having finally taken the time to put this machine to the test, I can honestly say this thing has more than enough power to satisfy the average homeowner or DIY’er. As I said in the title: this thing is a beast! Mine arrived complete and undamaged. Other reviewers reported scratches and dents but that was not my experience at all. Assembly was quick and easy. My shipment contained a quart of Amsoil synthetic 10W-30 for the engine crankcase but I have seen other reviewers that got their oil in a plastic pouch. Once assembled, the crankcase filled with the supplied oil, and the fuel tank filled 1/2 way, I hooked up the garden hose and bled the air out for 30+ seconds as recommended. Set the throttle to half-way and closed the choke and gave the starter a quick pull and it fired right up on the first attempt. After allowing the engine to run at partial throttle with the trigger open to keep the water flowing and the pump cooled for a few minutes, I increased the engine speed to approximately 3/4 and started cleaning the concrete patio as my first project with this unit. The pressure even at less than wide open on the Honda GX390 was more than enough to get the accumulated grime blasted off effortlessly. Next up, I connected my 15” surface cleaner which really sped up the process. The 4240 pressure and water flow are a perfect match for the Karcher 15” surface cleaner. With all of the positive attributes of this machine, there is one thing that I feel is a negative: the hose. It’s more than long enough for most jobs but the stiffness makes moving around with it a real challenge. Given the higher than average PSI capabilities of the ALH-4240 it’s not surprising that the pressure hose is more on the stiff side, but as others have commented, it would be a good idea to upgrade to a better hose. Honestly, at this price point, a better quality hose should come with it. Overall, the ALH-4240 is a great pressure washer that has all of the power that the average person could want for DIY use. The high PSI and GPM make short work out of even the toughest cleaning projects. Time will tell if it lives up to the Simpson advertised claims of dependability and reliability. ... show more
Reviewed in the United States on September 17, 2024 by Kenneth B.
    • Strong and reliable (detailed review over the year)
Style: 3400 PSI Honda GX200
Wanted to wait for some time to pass before making a real a review on my pressure washer. Purchased in sep 2021 and it’s now Jan 2025, so I have used it for 3 warm seasons since I only use it during the warmer months in PA. Did A LOT of researching before pulling the trigger on getting this unit. Some might think it’s expensive for someone who may only use it for home use and not commercial, but it’s perfect and reliable! I wanted something that would be versatile and beneficial with all projects. I always do the recommended maintenance and when storing for winter I winterize it. Maintenance is key for anything and I believe taking care of this will make it last for years of use. Main selling points for me and things I like: - CAT AAA pump, Honda engine, warranty, GPM, heavy duty but “light weight” frame/wheels, and being able to not worry about damaging the pressure washer if you release the handle while it’s running (not something I do often but know that’s a big no no when it comes to other pressure washers that don’t have the feature to allow this. High PSI and also the ability to lower the rpm’s to use it for lighter duty tasks. My complaints over the years: - The rubber feet that come with this unit are garbage, plan on replacing them with bigger and better feet because these ones will not last and the pressure washer will walk around on you. - I wish there was a better design for changing the oil, it’s a pain in the butt but with the right set up it wouldn’t be a big deal - It a little awkward when wheeling it around but it’s not a big deal and is only heavy if you are picking it up by yourself to go up stairs or things like that. Overall I would highly recommend this and would purchase again! Hope this helps you :) ... show more
Reviewed in the United States on February 2, 2025 by Tim
    • Powerful BUT it is VERY HARD to START, NO customer service al all
Style: 3400 PSI Honda GX200
When it is working, it’s so powerful and smooth. Design and built seems and feels high end and durable, however, it is VERY HARD to start. If the first full doesn’t start, no chance to start at second attempt. I owned gas pressure washer for almost 30 years, none of previous ones does that. It is way more pickier than my previous Excel. The Excel lasts 15 years for me. First, it is picky about fresh gas, it refused to start while brand new maybe just because the gas was two months old, now again, it won't start because the gas was almost two months again. My previous Excel can use gas more than 6 months old, Simpson engine is a princess--high maintenance picky machine. Second, the pressure built up so fast, if the first attempt wasn't successful, no way to start at the second. Even my neighbor who got a cheaper model of Simpson said this one is TIGHT. I'm so SCARED of starting it every time, needs a lot of pulls and luck. Excel only needs about 1-2 seconds of release pressure , this Simpson really needs 30 seconds to try my second luck. To start the machine is a TWO man job, one has to release the trigger on the other end constantly!! Third, even if I'm lucky to start it, it coughs/farts often and I have to be very careful to move the engine from choke to normal SLOWLY, otherwise it stops. Fourth, it gives farts loud several times when switched to off position. None of my previous ones did that, not once. Now I have to get used to the random noise after spending $800! Ordered one electric pressure washer last night, I'm done with the gas one especially with NO HELP from the seller...weird from day 1 Tech support is NOT responsive at all! My question never received answer. ... show more
Reviewed in the United States on March 8, 2022 by ContaxRTSII

Can't find a product?

Find it on Amazon first, then paste the link below.