Your First Pressure Washer, Choose for the Job Before the PSI

Start with the surface and the mess

Write down your main job before comparing machines: washing a car, cleaning outdoor furniture or covering a large paved area. Then check the surface maker’s cleaning instructions. Treat “light duty” and “heavy duty” as shopping categories, not permission to spray a particular finish.

The illustration separates everyday cleaning from more aggressive work. Stripping paint is a different project from washing dirt off; don’t size your first machine around it unless that is actually the job.

For ordinary household outdoor cleaning, start with cold water. Repeated grease removal is a reason to investigate hot-water equipment: heat helps loosen oils, but the heating system adds complexity. That is a buying distinction, not a promise that every oil stain will disappear. Kärcher explains the hot-water tradeoff.

If you meant kitchen or bathroom cleaning, reconsider the category. Domestic steam cleaners have indoor cleaning applications; our steam-cleaner selection guide helps you compare formats. Check the surface manufacturer’s approval before choosing steam.

Compare pressure and flow on the same basis

PSI measures pressure; GPM measures water flow. Pressure helps loosen dirt, while flow carries it away. CU, or cleaning units, multiplies PSI by GPM: 2,000 × 2 = 4,000 CU. It is a comparison aid, not a cleaning-time prediction. AR Blue Clean explains these measures and their limits.

Ask for working pressure and flow under comparable conditions, rather than multiplying unrelated maximum figures. For a large area, put flow beside pressure on your shortlist. A documented test method helps too: CETA CPC 100 evaluates advertised performance. It does not certify that a nozzle is safe for your car’s paint.

Check the outlet and tap before choosing the motor

• Start with electric when a suitable outlet reaches your work area and you want to avoid engine upkeep.
• Compare gas when independence from an electrical supply matters enough to accept more noise, fumes, weight and maintenance. These are typical tradeoffs, not fixed performance tiers. Kärcher compares both power sources.

Read the exact regional manual. For example, the US K1700 specifies 120 V and prohibits extension cords. Its maximum output is 1.2 GPM, yet its required inlet supply is at least 2 GPM. Measure flow from your intended supply hose against the machine’s inlet requirement. K1700 manual.

Gas also needs a safe operating location. The CDC says to operate outdoors, at least 20 feet from windows, doors and vents. An open garage is not your workaround. CDC pressure-washer safety.

Compare the complete setup, not just the machine

Check the included hose length, spray gun, nozzles and accessory connections before pricing extras. Buy around the reach and surfaces you actually need.

For a large flat paved area, consider a surface-cleaner attachment: its rotating spray bar covers a wider path. Match the exact washer to the attachment’s approved pressure range and connection; the same brand name alone is not enough. Kärcher’s compatibility guide shows why this check matters. For small spot jobs, leave it off the initial shopping list.

Include storage in the decision. Electric does not mean you can leave the pump wet through freezing weather; follow the model’s draining and storage instructions. Kärcher’s electric-washer care guidance.

Make the final choice and plan the first use

Order when you can name the job, verify water and power requirements, and confirm the included tools fit. If a seller cannot supply the manual or clarify the ratings, keep comparing.

Before spraying, follow the manual’s protective-equipment instructions and test an inconspicuous patch. Switch off and release pressure before removing parts. K1700 safety instructions.

Test the electrical shock-protection device before use, keep connections dry and keep people away from the jet. A high-pressure spray wound needs prompt medical attention even if it looks small. CDC safety guidance.