How does pressure washer work?

Pressure washers are wonderful tools, aren’t they? Reducing the cleaning time by half with twice the cleaning prowess, their importance is severely underrated. 

The main function that pressure washers carry out is that they propel pressurized water onto the surface you’re projecting at. The speed and intensity penetrate the layers of dirt and grime that have accumulated at the said surface, which makes it easier to clean them off.

If you’ve wondered, at any stage, how pressure washers operate, then you’re in the right place. In this segment, our main goal is to acquaint you with how exactly a pressure washer works. 

Parts of a pressure washer

Contrary to popular opinions, pressure washers aren’t that complicated. To put it simply, it’s a fusion of an electrical motor with a water pump. When working in conjunction, these two come together to create unparalleled cleaning and wash up.

On face value, the pressure washer has a source of water, such as a sink. It then reroutes the water in its internal machinery, and then lets it out in a pressurized manner. 

To better understand how that happens, we must first discuss the major components of a pressure washer.


This is where the magic starts. 

The water inlet is the source of the water for the washer. The water inlet, in its absolute essence, is a pipe that connects the washer to a source, such as a sink.

To keep your machinery safe, the water inlet also has a filter in it. This filter ensures that dirt particles and other components aren’t sucked into the machinery.

Other than clogging, this can actually cause structural damage because these things will be sent out with high velocities on propulsion.

Electrical/Gas motor

As the name implies, the motor is the mechanism by which the pressure washer operates. 

Smaller models are often electrical based and are optimal for indoor use. These models are often a simple plug and play and aren’t too complex to handle. 

For bigger heavy-duty models, the motor is often gas based. Similar to lawnmowers, these models technically work on the same energy input.

Gas based motors also produce more noise which is why they are better suited for outdoor works. Additionally, if you work in a region where dealing with electrical wires might be hazardous, then gas motors are your best bet.

High pressure hose

A high pressure hose is the pipe that is connected to the washer at one end, and to a cleaning attachment on the other end. The latter is, obviously, of your own choosing.

Generally speaking, normal pipes cannot withstand the high amount of pressure that is generated by washers. Hence, to make sure that the hose doesn’t give up on you, it is made from high-density plastic.

To reinforce its structural integrity, it has wire mesh embedded into it as well.

A rule of thumb to always follow is that the high-pressure hose you use should always be of a higher rating than the model you’re dealing with. This is to prevent any damage or hose breakdown.

To make the mathematics easier, a hose should be about thrice as capable as the motor.

Water pump

If we’re speaking in analogies, then the water pump is the main driving force, the heart of the operation.

The water pump is driven by the motor that you’re working with. When the pump is pulled in a particular way, it sucks in water from the source. When the pump is pulled in the opposite direction, the water is let out in a highly pressurized jet.

Water pumps are mainly designed to handle a good flow of water. This is normally around 1 to 2 gallons per minute.

Cleaning attachments

Cleaning attachments are more like a privilege as opposed to a necessity. This feature is entirely dependent on you, and can vary from individual to individual.

There is a wide array of options to choose from when it comes to attachments. Common options include a trigger gun or a rotating brush.

The former is driven by a trigger; you press the trigger and the water will flow out. The latter is pretty self-explanatory and is pretty good for cleaning out flat surfaces.

RCDs (Optional)

RCDs, also known as Residual Current Devices, are ground fault circuit breakers that are often present in most pressure washers.

It’s common knowledge that electricity and water don’t mix well. To keep the user safe at all times and under the worst of circumstances, RCDs are often present in a pressure washer. They take over if there is even the slightest chance of an electrical fault.

Putting it all together

Now that we’ve built the essential machinery and the fundamentals behind a pressure washer, it’s time to put it all together and see what we can work with.

After taking care of the setup and making the relevant connections, you turn the motor on. 

There are two containers which hold water and detergent simultaneously. When the faucet pulls in water, it is momentarily kept in this container. 

An electrical/gas motor, meanwhile, will power up the washer.

In the washer, the detergent and the water (that has been pulled) are mixed together thoroughly to make a solution. In most washers, the temperature is maintained between 50 to 70 degrees.

When the pump is pulled, water is propelled out in a high pressurized jet. In most cases, the pressure can often damage fragile objects, which is why it’s always advised to be careful around them. 

To make the effects more apparent, the nozzles are often quite small. These increase the pressure flow even more.

A great thing to keep in mind is that utilizing this machinery will save you a lot of water in the long run.


It’s fair to say that pressure washers are a blessing, especially if you want to work smarter, not harder. Now that you’ve understood the basics, it’s high time you set out and get the best model for yourself!