How to Use a Pressure Washer

Before you get started, decide if you'll buy or rent a pressure washer. If this is a small, once-a-year project that calls for a rented pressure washer, we have all your rental needs in one place. 

Decide which type of pressure washer is right for you based on your job. For medium to heavy duty jobs, like cleaning siding or removing oil stains from a driveway, a gas-powered pressure washer is recommended. Gas-powered pressure washers use about 3,000 PSI (pounds per square inch), making them incredibly powerful. 

For light duty jobs such as cleaning your car or grill, an electric pressure washer is ideal. Using about 1300-1400 PSI, electric pressure washers are portable and efficient in small areas, as well as on painted surfaces.

This is also a good time to decide if you will need accessories like pressure washer hoses or extension wands.

Here is a breakdown of what the colors on pressure washer nozzles mean.

• Red: 0-degree spray, ideal for hard-to-remove dirt and oil. 
• Yellow: 15-degree spray, optimal for stripping a deck or siding.  
• Green: 25-degree spray, ideal for cleaning dirt and debris from cars, driveways or concrete.
• White: 40-degree spray, perfect for areas near windows or light fixtures.  
• Black: 65-degree spray, usually used for cleaning cars or for smaller projects that need soap and water.

Tip: Most heavy-duty, gas-powered washers will come with four or five colored nozzles to attach to your pressure washer spray gun. Each nozzle varies in degree of spray they allow. Smaller, electric pressure washers with less than 2000 PSI will typically come with one. 

Once a nozzle is selected, connect the pressure washer to the water supply line with a garden hose.

• Be sure the hose is connected to your home’s water supply.
• Connect the hose to the pressure washer's water inlet.
• Double-check that all connections are tight. 

Tip: You can check that your home's water source will provide the right amount of pressure by testing it in a bucket prior to hooking up the pressure washer. Simply time how long it takes to fill a 5-gallon bucket. If it takes two minutes or less, you should be good to start. 

Next, turn on the water supply and test out the nozzle by squeezing the trigger on the pressure washer head.

• Start on the lowest setting at first to avoid any kickback from the machine. 
• Squeeze the trigger for about one minute to let out any excess air. 
• Let go of the trigger and adjust the nozzle to your project's needs. 

You can now turn on the pressure washer and begin your project. There are different ways to start up an electric vs. gas-powered pressure washer. 

For gas: 

• Add oil and fuel based on your pressure washer’s recommendations.
• Set fuel valve to "open," turn on the switch and set choke lever to “full start.”
• Pull starter rope and let it run for 10 seconds.
• Move choke to “run” position. 

For electric:

• Plug the machine into a grounded outlet and turn it on.  

For even cleaning, use a grid pattern: Start at the top of the project and move side to side. A wider spray equals faster cleaning, while a tighter spray equals deeper cleaning.

Tip: Hold the nozzle tip about four inches away from the area you are cleaning. Move closer for harder to reach stains.

When it's time to turn off the machine, follow these steps: 

• Release the trigger and turn on the safety lock. This will help to avoid any unnecessary spraying or start-ups. 
• Turn off the water source. Don’t immediately detach the hose from the machine if the main water source is still on. Pressure has built up in the hose and could cause injury. 
• Now, turn off the safety lock on the pressure washer and pull the trigger to remove any excess water and pressure. 

• Carefully detach the garden hose from the pressure washer's water inlet. You can also disconnect the hose from the home's water supply and store your hose. 
• Store your pressure washer in a dry, indoor area. Return the rental to your local The Home Depot store. 

Keep these tips and tricks in mind when using a pressure washer:

• Always be sure your pressure washer is on a flat surface. 
• For those with a deck, it’s recommended you pressure wash at least once or twice a year. High pressure from a gas power washer and a nozzle at a 45-degree angle should get the job done. 
• A wider spray equals faster cleaning, while tighter spray equals deeper cleaning.
• Clean your car with an electric pressure washer. Use pressure washer surface cleaner or detergent. 
• For garage floors and other concrete surfaces, a gas or electric pressure washer can be used on medium to high pressure with a nozzle at a 45-degree angle. 
• When pressure washing siding, always keep the nozzle about 4-feet away from the siding so as not to damage the paint or surface. 
• Always avoid spraying windows with a pressure washer, and be sure to keep the spray away from exterior lighting and fixtures. 
• Never pressure wash while on a ladder. The pressure could cause you to lose your balance. 
• Always wear safety goggles, closed-toe shoes or boots and other safety gear. 
• Do not use a gas power washer in an enclosed space due to fumes. 
• Stay at least six feet away from power lines when operating a pressure washer.