No socket, no limit · review
Axial cam with thermal relief and low-oil shutdown, at 3300 PSI and 2.4 GPM.
Where this ends up The only axial cam machine on this shelf with both a thermal relief valve and low-oil shutdown — the two features that keep the pump and the engine alive. Eighty dollars above the Westinghouse, and it publishes no warranty where the Westinghouse publishes three years.
This is the reason to pay the premium, and it is worth understanding what each one saves.
Thermal relief protects the pump. Release the trigger and the engine keeps running, so the pump keeps turning with water circulating inside it and nowhere to escape. Within a minute or two it is hot enough to wreck the seals and valves. The valve dumps that water on the ground before it happens.
That is the commonest way a pressure washer pump dies, and it happens to people who stop to move a hose and leave the engine running.
Published here, and on all five Simpsons. Not published on the three Westinghouse machines or the PowerSmart.
Low-oil shutdown protects the engine. It cuts the ignition when oil falls below a threshold, instead of letting the engine run itself dry and seize. On a machine used three or four times a year, after months standing in a garage, that is the realistic failure mode.
Published here and on the four Honda-engined Simpsons. Absent from the three Westinghouse listings, the PowerSmart, and the $899.99 Simpson CRX.
So a $429 machine carries protection that a machine at more than twice the price does not publish.
The Westinghouse WPX3400 at $349 gives:
3400 PSI / 2.6 GPM — 8840 cleaning units · a half gallon onboard soap tank · 12 inch never-flat wheels · a stated M22 accessory compatibility list · three years of service, labor and parts with a nationwide network
This gives:
3300 PSI / 2.4 GPM — 7920 units, about ten per cent less · thermal relief · low-oil shutdown · 10 inch pneumatic tires · a welded powder-coated steel frame · published dimensions · no warranty
So the eighty dollars buys protection instead of performance, and gives up a written promise in exchange.
Both use an axial cam pump. The Westinghouse calls its version “maintenance-free”, which means sealed and unserviceable; this one calls it “OEM Technologies” and says the same thing by omission. Either way the pump is replaced rather than rebuilt, and rated in the low hundreds of hours against the thousands a triplex plunger pump manages.
The honest summary: if you will remember not to idle it with the trigger off, the Westinghouse is better value and carries the only warranty on this shelf. If you will not, this is the machine that survives the mistake.
3300 × 2.4 = 7920. The industry measure is PSI × GPM, and no listing here publishes it.
Simpson CRX 4400 — 17,600 · Simpson ALH4240 — 16,800 · Simpson PS60869 — 14,000 · PowerSmart — 9500 · Simpson Aluminum 3600 — 9000 · Westinghouse WPX3400 — 8840 · Simpson PS3228 and PS61002 — 8250 · Westinghouse WPX3200 — 8000 · this — 7920 · Westinghouse WPX3000 — 6900
Second lowest on the shelf, and the lowest of anything above three hundred dollars.
Pressure cuts, flow rinses. At 2.4 GPM this is a tier below the 2.5 and 2.6 GPM machines on rinsing speed, which on a driveway is what you feel — the dirt is loosened and then pushed, and pushing takes water.
What matters for one specific accessory: a surface cleaner has no motor, and its nozzles are spun by the water leaving them, so flow turns the head. Most want 2 GPM or more, and 2.4 will drive a twelve to fourteen inch head properly. A sixteen or twenty inch head wants more.
The listing’s own use cases are well chosen for the figure: “decks, patios, siding, and prepping exteriors for painting”. Paint preparation is a pressure job rather than a volume job, and 3300 PSI with the 15° tip is the right tool for it.
10 inch pneumatic, matching the PowerSmart and three Simpsons.
The three Westinghouse machines use 12 inch never-flat solid wheels instead. The trade is real in both directions: a solid wheel cannot puncture and never needs air, so a machine left all winter rolls in spring. An air tire deforms and climbs where a solid one skids and sends every bump into the frame.
All five Simpson listings make the case in identical words — “roll smoothly over gravel, grass, and curbs” — and this listing says “smooth maneuvering across uneven terrain”.
At 29,030 g (1024 oz) across a gravel drive, air is the better choice.
Dimensions: 41 × 21 × 24 inches, published. Four listings on this shelf publish none at all, and on a machine that has to live somewhere in a garage that is a figure you want before ordering. The three big Simpsons publish theirs too — 38 × 23.5 × 29 inches for the two largest.
The welded, powder-coated steel frame is the standard here: the five Simpsons all publish the same construction, except the two Aluminum Series models which use “aircraft grade aluminum” — and which, at 78 and 133 lb, are not lighter than the steel ones.
“Maintain max fuel level 1/2 inch below filler neck to prevent spillage.”
A small instruction, and the sort of thing a listing earns trust by including.
Petrol expands as it warms. A tank filled to the brim in a cool garage pushes fuel out of the cap vent once the engine has run — onto a hot engine, down the frame, and onto the drive. Half an inch of air absorbs it.
Two Simpson listings carry the same note word for word, and all three also share the other piece of candour: “Factory-tested pressure washers may contain minimal residual fuel or odors.”
So it arrives having been run, with fuel already in it. Which is reassuring about quality control and is also why it smells.
What no listing on this shelf mentions is the other half of fuel care: stale petrol in a carburettor is the commonest reason one of these will not start the following spring. A stabiliser in the tank, or draining it before storage, is worth more than any specification here.
No warranty, and this is the significant omission. The three Westinghouse machines publish “3-Year Limited Service, Labor, and Parts Coverage with Nationwide Customer Service and Support Network”. The other eight listings on this shelf — this included, and all five Simpsons — publish nothing.
No soap tank. The WPX3200 and WPX3400 both publish a “Half Gallon Onboard Soap Tank”, the PowerSmart an onboard tank, the WPX3000 a “detergent siphon hose”. This listing publishes a soap nozzle and no tank or siphon, so how detergent reaches the gun is unstated.
No unloader, which all five Simpson triplex pumps publish — the valve that diverts flow at the pump when the trigger is released, and the companion to thermal relief.
No hose bore, where the WPX3000 publishes 0.25 inches and three Simpson listings publish 5/16 or 3/8 inch by length.
No PWMA certification, which only the PowerSmart at $259.99 claims — the single independently verified PSI figure on this shelf.
No fuel tank capacity, which all three Westinghouse listings publish (0.9, 0.95 and 1 gallon).
Read on the day this page was built: $430 at the American Amazon shop.
Read from Keepa on the day this page was last revised; stock and price both move without notice.
Prices quoted in this text were read on 2026-10-04. The live price is at the top of the page.
| Thermal relief | Yes — a valve against overheating, which the three Westinghouses do not publish |
|---|---|
| Low-oil shutdown | Yes — on a 208cc DeWalt engine |
| Output | 3300 PSI at 2.4 GPM — 7920 cleaning units |
| Pump | OEM Technologies axial cam |
| Frame | Welded steel, powder-coated |
| Tires | 10 inch pneumatic |
| Hose | 25 feet, abrasion-resistant |
| Nozzles | Five quick-connect, with a 16 inch steel wand |
| Weight | 29,030 g (1024 oz) |
| Dimensions | 41 × 21 × 24 inches, published |
| Compliance | 49-state compliant |
| Fuel note | Keep the level half an inch below the filler neck to prevent spillage |
| Warranty | Not published |
| Amazon reference | B09ZHG2NDM |
| EAN | 0636893407369 |
The two components that cost the most to replace, and this is the only machine under five hundred dollars here with both. Thermal relief protects the pump. When you release the trigger the engine keeps running, so the pump keeps turning with water circulating inside it and nowhere to go — within a minute or two it is hot enough to destroy seals and valves. The valve dumps that water on the ground first. This listing publishes "Thermal relief valve prevents overheating for long-lasting performance"; all five Simpsons publish one too; the three Westinghouse machines and the PowerSmart publish none. Low-oil shutdown protects the engine. It cuts the ignition when the oil level falls below a threshold, instead of letting the engine seize — which on a machine used a few times a year, after months in a garage, is the realistic failure. This publishes it, and so do the four Honda-engined Simpsons. It is absent from the three Westinghouse listings, the PowerSmart, and the $899.99 Simpson CRX. So a $429 machine has protection a machine at more than twice the price does not publish.
Not for output, and the trade is clear once laid out. The Westinghouse WPX3400 at $349 delivers 3400 PSI / 2.6 GPM — 8840 cleaning units — with a half gallon onboard soap tank, never-flat wheels, a stated M22 accessory compatibility list, and three years of service, labor and parts. This delivers 3300 PSI / 2.4 GPM — 7920 units, about ten per cent less — with thermal relief, low-oil shutdown, pneumatic tires, a welded powder-coated steel frame, published dimensions, and no warranty at all. So the eighty dollars buys protection rather than performance: a pump less likely to cook and an engine less likely to seize, against a longer promise if either does. Both use an axial cam pump — sealed, unserviceable, rated in the low hundreds of hours rather than the thousands a triplex plunger pump manages. Neither publishes a soap tank on this one, which the Westinghouse does. If you will remember not to idle it with the trigger off, the Westinghouse is better value; if you will not, this is the safer machine.
Spillage, and it is a genuinely useful instruction that three listings on this shelf repeat. The bullet reads: "Maintain max fuel level 1/2 inch below filler neck to prevent spillage." Petrol expands as it warms, and a tank filled to the brim in a cool garage will push fuel out of the cap vent once the engine has been running — onto a hot engine, down the frame, and onto whatever the machine is standing on. Half an inch of air at the top absorbs that. The two Simpson listings with the same note — the CRX 4400 and the ALH4240 both say "Keep max fuel level 1/2 Inch below bottom of filler neck to avoid spillage" — put it alongside the other piece of honesty these listings share: the machine is "100% functionally tested in factory" and "may contain minimum residual fuel/oil or fuel odor". So it arrives having been run, with fuel already in it. What no listing on this shelf mentions is the other half of fuel care: stale petrol in a carburettor is the commonest reason one of these will not start the following spring.
cleaning machines from the same category, at nearby prices. Only what all of them publish is shown: a column with holes compares nothing.
| Model | Price | Thermal relief | Low-oil shutdown | Output | Pump |
|---|---|---|---|---|---|
| DeWalt DXPW3300-S | $430 | Yes — a valve against overheating, which the three Westinghouses do not publish | Yes — on a 208cc DeWalt engine | 3300 PSI at 2.4 GPM — 7920 cleaning units | OEM Technologies axial cam |
| Westinghouse WPX3400 | $350 | Not published | Not published | 3400 PSI and 2.6 GPM — 8840 cleaning units, the highest flow of the three Westinghouses | Maintenance-free axial cam |
| Westinghouse WPX3200 | $330 | Not published | Not published | 3200 PSI and 2.5 GPM — 8000 cleaning units | Maintenance-free axial cam |
| Westinghouse WPX3000 | $300 | Not published | Not published | 3000 PSI and 2.3 GPM — 6900 cleaning units, the lowest on this shelf | Maintenance-free axial cam — see the FAQ on what that means |
Details checked on October 4, 2026.
A residential user who wants the engine and pump protected rather than guaranteed
Amazon reports what buyers took in the month before this page was last checked: at least 400.
The figure is a floor, rounded by Amazon, and read through Keepa — it says what buyers picked, not what a maker claims.
Specifications: the manufacturer sheet for cleaning machines and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
2,200 PSI (≈ 152 bar) · 2.3 GPM · single-cylinder air-cooled
The most modest petrol machine here, and the only one listed on all six Amazon stores.
Best for: Large gardens and outbuildings without power, where 150 bar is plenty
170–190 bar · 3,400 rpm · axial cam pump · self-priming
A modest pressure range honestly stated, on an axial pump — the entry to petrol here.
Best for: Occasional work away from a socket — a smallholding, a boat yard, a second property
234 bar working · 590 l/h · 5.9 hp four-stroke · 9 m (30 ft) hose
The only machine on this site that publishes a working pressure and a flow rate together.
Best for: Farmyards, contractors and large properties without power at the far end
