How to use an electric pressure washer

Different PSI for Different Jobs

What’s great about pressure washers is that they’re incredibly versatile pieces of equipment, with home and commercial applications outside of simply blasting water onto surfaces.

One of the first things to realise about your pressure washer is that it has different nozzle attachments and using these appropriately can be the difference between a great clean and a great deal of damage to your surface.

Nozzle Types

Pressure washer nozzles will usually come colour-coded, with each colour of nozzle indicating a change in the tightness of the water’s spray pattern as it is released from the machine.

We’re going to use the colour-coding system of Karcher nozzles to give you an example of how nozzles are often organised, but different brands might use their own colour-coding, so be sure to check your manual, and the nozzle itself, for the specifics of your machine.

Red 0° Nozzle — Produces the most powerful jet of water and should be reserved for cleaning away caked on mud, tar, and stubborn algae from tougher surfaces like brick and concrete. Never use this on your car as it can damage the topcoat and don’t try to clean windows as you could damage the seals or break the glass.

Yellow 15° Nozzle ­— Great for paint preparation, cleaning boats, and removing algae and moss build ups. Treat this in a similar way to the 0° nozzle and reserve it for hardy surfaces that can withstand some punishment.

Green 25° Nozzle — For removing common dirt, soil, and grime from surfaces. This nozzle is great for cleaning tyres, as it has enough power to remove dried mud from your treads but has a cone spray pattern that will avoid direct pressure that can weaken the tyre walls.

White 40° Nozzle — Use for rinsing and cleaning more delicate surfaces such as windows, your car or ute, or for performing soft washing. This will be your go-to nozzle for cleaning your deck, washing windows, and a good starting point before you crank the pressure up on tougher surfaces.

Black 65° Nozzle — This nozzle will usually have a maximum force of 500 PSI and is generally used for applying soap. It will usually use your pressure washer’s chemical application tube to draw in chemicals and soaps you have in the machine and apply them through the nozzle. This nozzle is also good for rinsing and when you want an even more delicate alternative to the white 40° attachment.

Turbo/Rotary Nozzle — Turbo Nozzles (also called Rotary Nozzles) are incredible powerful nozzles that use a circular motion to rotate a zero-degree nozzle at high speeds to achieve water pressure close to ten times that of a standard pressure washer nozzle.

Great for stripping chipped paint, cleaning tough concrete surfaces of deep stains, and dealing with anything a standard 0° nozzle can’t handle.

These nozzles are only for the most challenging power cleaning jobs and should be used with extreme care, as the water that comes from them can cause injury to yourself and others and damage to delicate surfaces.

Assembling Your Pressure Washer

Electric pressure washers don’t have a huge number of moving parts, but most machines require some assembly before you can start raining down jets of water on those nasty moss patches in the driveway.

Step 1: Connect the Wand

The business end of your pressure washer will usually come in two separate parts, with a trigger handle that is used for pumping the water out and a wand that can be changed out for other specialised attachments like telescopic lances for extra reach or brushes for scrubbing tough stains.

You’ll simply need to lock these two pieces together by clicking them into place and twisting to ensure they’re secure.

Step 2: Select a Nozzle

As mentioned earlier, different nozzles will give you different levels of pressure, so select the correct nozzle for the job and then attach it to your wand.

Step 3: Attach the Hose

Now you’ll need to connect the hose between your pressure washer and the trigger handle. Both ends will be identical, and you’ll just need to attach and tighten them until they’re firmly in place.

Step 4: Hook Up the Garden Hose

Attach your garden hose to the black threaded connector on the pressure washer and make sure it clicks into place.

Step 5: Turn the Hose On

Time to get that water flowing! Check all your connections and then turn the water on as high as it’ll go to make sure you get good water flow.

Step 6: Plug the Pressure Washer In

Now that the water is ready, plug your pressure washer into a wall socket to get power to the machine. If you’re going to use an extension cord, then be sure the connection point is kept away from water.

Step 7: Switch the Pressure Washer On

Locate the power switch on your pressure washer, which might be on the top or front of the machine and turn it to the on position. You should hear the machine come to life and the water start to pressurise, so if this doesn’t happen, you might need to press the reset button on your GFCI outlet.

Using Your Pressure Washer

While you’re probably keen to get the water flowing and your car or deck clean as a whistle, there are a few things to keep in mind when pressure washing.

Pressure Washer Safety

You’ll want to wear closed-toe shoes when you pressure wash and pants that will protect your lower legs. High pressure water can be painful when it makes contact with your skin and can cause abrasions, so proper safety and protection is important when using your machine.

It might seem obvious, but never point the pressure washer hose at animals or other people — even if the dog is in desperate need of a bath.

Check Your Pressure

If you’re unsure of which nozzle is the correct choice for the surface you’re washing, start with the 40° low pressure nozzle first and work your way up to higher pressure when you’re sure the surface can handle it.

Clean Top to Bottom

If you’re cleaning multiple different surfaces, such as your outside furniture and decking, make sure you clean your table and chairs first and the deck second. This also applies to cleaning the walls of your house or any other large vertical surface, where you’ll want to clean the top first so that the dirt being removed isn’t running down into the area you’ve just washed.

Keep Your Distance

For any general surface cleaning you’re doing, always pressure wash from a distance. Start about a metre away and only move closer if you’re dealing with a particularly stubborn stain on a tough surface like concrete or tile.

Careful of Cables

Watch out for your cords. Always try to be mindful of the cord as you move around with your pressure washer, as it can be a tripping hazard, especially with a soaking wet surface below your feet.

If you’re using an extension cable, be mindful of the connection point, which you might want to put up onto a chair or raised surface while you clean, to keep it out of contact with water.

Time to Get Pressure Washing

Now that you’re acquainted with the basics of your pressure washer, you’re ready to start dealing with those odd jobs that have been building up around the house. The great thing about pressure washers from major brands like Karcher and Mechpro Blue is that they come with a ton of handy pressure washer accessories designed to make the job easier.

So, if you’ve got a tough cleaning job that needs a tougher clean, browse Repco online or head into your local store to see our full range of pressure washing products.