How Does a Pressure Washer Work?

December 14, 2023 @ 12:40 am

how does a pressure washer work

If you’ve never handled one before, a pressure washer may look a little daunting and have you ever asked yourself how do pressure washers work?

However, no matter how huge, technical, or heavy-looking they may appear, all pressure washers work along with the very simplest of processes.

And that’s good news!  After all, we simply need them to do a superb cleaning job on the things we find so difficult to keep dirt-free.

Universally, pressure washers work by driving water at excessive speeds through a tiny outlet or nozzle. For domestic electric pressure washers, as opposed to industrial types, the water supply usually comes from a household tap or faucet.

When the pressure washer is turned on, an electric motor sets the pump in motion, pressurising the water within the machine’s tank.

Pressure washers usually work towards a top pressure of approximately 110 to 160 ‘bar’. The term ‘bar’ is used to describe the vivacity with which the forced water from your pressure washer meets the surface of whatever you are cleaning.

When the ideal water force is achieved, the electric motor switches itself off leaving pressurised water ready for you to squeeze your trigger again.

Most pressure washers come with a connected hose and spray nozzle with a trigger, which needs to be pressed when you want to begin your cleaning.

Just like a toy water pistol, aim and shoot with precision. Remember that pressurised water comes out incredibly fast and forcefully.

This is caused by the use of a nozzle to decrease or increase the size of the water flow which, in turn, affects the force. The bigger the nozzle opening, the less pressure the water will have when it is jettisoned out of the pistol. The narrower the nozzle opening, the more powerful the water blast will be.

In order to keep up the pressure, whenever you press the trigger, the motor leaps into action again.

Although at first use, some pressure washers might look and sound like big angry beasts, in general, they have the potential to solve many of your large scale or outdoor grime problems.

And, if well maintained, they are likely to work safely and soundly for many years.

Of course, there are many variations of pressure washers, specifically designed to tackle different aspects of cleaning.

Why do pressure washers work

Pressure washers work because the gallons of high-pressured water shooting from the nozzle are fantastic at getting under the stubborn particles of grime attached to our patios, decks and flagging stones, our beloved holiday caravans and motor homes, our dirt-ridden driveways and our mud-encrusted bicycles,

That’s in addition to our beloved cars of all shapes and sizes.

The kinetic energy unleashed through the jet stream of water via the hose and trigger of the pressure washing machine literally sledgehammers the dirt away and, with the option to use detergent or not, it makes the clean-up even more simple.

Which? Magazine explains that a pressure washer is “essentially a motorised hosepipe” that relies on a pump to “create a high-pressure flow of water that dislodges dirt more quickly and effectively than you can with a scrubbing brush or hose alone.”

When using a pressure washer, be sure to follow instructions carefully. Electric and petrol pressure washers need differentiated handling and as such a great debate as to which is better, Electric vs Petrol has been raging in the pressure washing communities for years.

Petrol-fuelled pressure washers run on a pull to start petrol 4-stroke engine and such require you to prime the choke and add petrol and oil before starting.

They are also prone to damage In the colder months so special care should be taken to winterize your pressure washer in order to properly maintain it.

Electric power washers are usually smaller and lighter and easier to store.

They usually start simply with the flick of a switch and the press of the trigger.

How do pressure washers work


Remember, in the end, a pressure washer works as well as you use it, maintain it, and focus on safety, that of your own and others.

Jeff Kirby
Jeff Kirby


Jeff is our head reviewer here at and has over 10 years in the commercial pressure washing business. What he doesn’t know about pressure washers isn’t worth knowing. 

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