The Simpson Aluminum ALH3425-S is a gas-powered pressure washer offering a maximum water pressure of 3600 PSI and flow of 2.5 GPM. (Read full specs)
Zoom on the Simpson ALH3425-S
In summary, the Simpson ALH3425-S is a heavy duty, commercial pressure washer, that offers an all-around versatile cleaning experience, and also:
- spot cleaning of hard, paintless surfaces and reaching far-away areas
- intense cleaning of hard, unpainted surfaces
- cleaning of painted and fragile surfaces
- application of detergent and cleaning solutions
With a 196 cc (5.5 hp) engine, its triplex pump delivers a pressure of 3600 PSI (roughly 60 times more than a standard garden hose) and a flow of up to 2.5 GPM (CETA-certified values), resulting in the Simpson ALH3425-S's cleaning power of 9000 Cleaning Units.
This gas-powered pressure washer’s Honda GX200 engine is started by a traditional pull-start mechanism.
Gasoline is stored in a steel fuel tank with a maximum capacity of 0.83 gallon.
Design & Handling
The wheelbarrow design of the Simpson ALH3425-S grants mobility and stability to the unit. The aluminum frame ensures the device's durability, as it will not rust. The handle adds to the ALH3425-S convenience of transport.
With a weight of 78 lbs, the unit can be easily maneuvered by most users. Since the 196 cc Honda GX200 engine and triplex pump account for a large part of its weight, Simpson's utilization of an aluminum frame keeps the unit at a reasonable weight. Since the ALH3425-S has a set of two 10" pneumatic wheels, it is still easily maneuvered and manipulated.
The Simpson ALH3425-S's package includes a spray gun, a wand, a pressure hose, 5 nozzles and a detergent injection feature, with a more detailed description below.
- Soap injection: Even though the device doesn't have a soap tank, detergent is supplied by a siphon hose. The Simpson ALH3425-S includes an automatic soap dilution mechanism, which will dilute the detergent using a 7:1 ratio. Whenever a soap nozzle is connected, the detergent is automatically added to the water.
- Pressure hose: The 35 ft ⌀5/16" high-pressure hose, which is included with the device, can be stored neatly on the unit itself when idle, using a set of convenient hooks.
- Spray gun and wand: A side hook enables you to easily store the included classic ergonomic spray gun and its steel wand.
- Nozzles: The following table illustrates the 5 included nozzles, along with the surfaces which they are the most suitable for.
|Concrete, brick, masonry||Use with caution||Suitable||Suitable||Suitable||Suitable|
|Siding, gutters, house||Not recommended||Use with caution||Use with caution||Suitable||Suitable|
|Fencing, deck, patio||Not recommended||Use with caution||Use with caution||Suitable||Suitable|
|Lawn equipment, boat, RV||Not recommended||Use with caution||Use with caution||Use with caution||Suitable|
Note: The shape of the nozzles above is for illustration purposes only and may differ.
Red cross: Not recommended. Green check: Suitable. Orange check: Use with caution.
- Onboard storage: With the Simpson ALH3425-S's handy storage area, you’ll always have all the necessary nozzles and accessories at hand and thus, you’ll be fully prepared for any job.
- Safety: Safety of operation is enhanced by a thermal relief valve (which helps to prevent internal pump damage), a low oil protection and a trigger lock mechanism (which prevents accidental operation).
- Accessories: Included with the Simpson ALH3425-S are also the owner's manual (opens in a new tab) and some basic documentation to get you promptly started, along with several accessories, such as oil, wand, spray gun, pressure hose and soap hose.
- Emissions: The Simpson ALH3425-S is EPA-approved and CARB-compliant. This means that this pressure washer can be bought and sold in each of the 50 states, including California.
The Simpson ALH3425-S's performance versus other pressure washers
The following charts are provided to give you an idea of how the key specs of the Simpson ALH3425-S compare to similarly priced pressure washers.
- With a maximum pressure output of 3600 PSI, the Simpson ALH3425-S finds itself in the expected pressure range among gas-powered units that cost between $600 and $700. If your priority is the highest possible power of the water stream, in this price range, we suggest checking out the Simpson PS60843, which reaches up to 4400 PSI.
- The achievable water flow of this washer, which reaches 2.5 GPM (gallons per minute) can be described as low, compared to other devices in its price range. If maximum rinsing efficiency is your top priority, one of the devices with the highest water flow in the same price range is the Simpson PS60843, with a GPM of 4.
- The ALH3425-S has 9000 Cleaning Units (PSI x GPM), which can be considered low in comparison to other gas-powered devices of this price. In case you are looking for the highest overall cleaning power, in this price range, one of the current champions is the Simpson PS60843 and its 17600 Cleaning Units.
As you can see from this interactive chart, when compared to other gas-powered washers between 9000 and 9500 Cleaning Units, the Simpson ALH3425-S is on the cheap side of the price range.
It can therefore be a really good buy if you're looking to acquire a budget pressure washer.
Features and Specifications
|Water||Cold (100°F max.)|
|Engine||196 cc 5.5 HP Honda GX200 OHV 4-stroke|
|Other model numbers||60689, 60768|
|Soap injection||Via siphon hose|
|Nozzles||0°, 15°, 25°, 40°, Soap|
|Quick connect nozzles||Yes|
|Hose||35 ft, ⌀5/16|
(L x W x H)
|Approx. 34 x 21 x 24 in|
|Wheels||2 wheels, ⌀10", pneumatic|
|Included accessories||Oil, steel wand, spray gun, high pressure hose, soap hose, 5 nozzles|
|Security||Low oil, trigger lock and thermal relief valve|
Unlike many websites, we did our best to research each of the specs above. That being said, we are not immune to making the occasional mistake or omission. Should you notice any missing or incorrect values, don't hesitate to suggest improvements so we can address the issue.
Simpson has over 50 years of experience making quality products for the outdoor power equipment industry. Part of the FNA Group based in Pleasant Prairie, Wisconsin since 2006, they are a vertically-integrated company, meaning most of the parts and accessories are manufactured and assembled by them. Their manufacturing facilities are international. With the company motto "Driven by Performance", Simpson continues to offer a great variety of pressure-washing systems for the homeowner or the professional contractor.
The Simpson ALH3425-S is covered under a warranty for up to 10 years. This warranty may be limited and may not cover all parts of the unit.
For more information about the warranty of Simpson pressure washers, please contact the Simpson Customer Support: 1-877-362-4271.