The Ultimate Pressure Washer Guide

Karcher pressure washer review clean home propertyThere is nothing nicer than cleaning your driveway or patio after a long, cold winter. A clean house is very attractive and is a great welcoming feature for family, friends and unexpected guests.

Choosing a pressure washer is confusing but read on and you will learn how to choose the best pressure washer for your job. A pressure washer buyers guide is also included below as well as a quick 5 point check list.

Pressure Washers

Pressure Washers, also known as power washers, are highly effective for many domestic cleaning purposes such as patio areas, driveways, brick and stone walls as well as vehicles.

Did you know that the average domestic pressure washer is 50 times more powerful than a garden hose? Not only that but because the water is highly pressurised and is ejected through a small nozzle pressure washers use 70%-80% less water than a garden hose.

Not only are pressure washers very effective but they are also super easy to use.


Pressure washers serve many domestic and commercial cleaning applications such as:

  • Walls
  • Steps
  • Swimming Pools
  • Farm Machinery
  • Footpaths
  • Bicycles
  • Motorbikes
  • Cars/Trucks/Vans etc
  • Boats
  • Home/Office Exteriors
  • Garden Furniture
  • Fences
  • Archways
  • Many More


There are many pressure washer brands on the market with the most popular being Karcher.

Other brands include Nilfisk, Bosch, Silverline, Wolf, Makita and Vax.

How Pressure Washers Work 

All pressure washers share the same functionality. Water enters the machine at low pressure and is pushed through the hose at high pressure by a pump which is driven by a petrol engine or electric motor.

Very basically when you start your pressure washer a crankshaft drives a camshaft inside the water pump that starts the pistons.

Fresh water enters the pressure washer through the water inlet which the water pump pressurises. The water gets driven up the high pressure hose, through your spray gun and out of the nozzle.

Pressure Washer Guide 

Electric Pressure Washers 

Electric pressure washers are ideal for smaller domestic jobs such as cleaning garden furniture or garden steps.

Due to the lack of engine they are quieter and lighter than petrol pressure washers. Electric pressure washers generally run cleaner than petrol models as well.

Electric pressure washers start by simply flipping a switch.

It is important to note the manufacturers instructions when it comes to plugging in the supplied power cord.

If you need to use an extension cord to operate the machine ensure that the instruction manual says this is ok, and if so then only use the recommended extension cord.

Power Cord Tips 

It is crucial to use the correct power cord for the job. If your power tool draws more current than your power cord can handle then you could start a fire!

If working outdoors chose an outdoor power cord as these have durable covers.

Check the cords gauge. The lower the gauge the higher the power.

Also check the length of the cord. The longer the cord the less power will be delivered to the power tool. 

Keep both gauge and cord length in mind when purchasing a power cord. 

Advantages of Electric Pressure Washers Karcher K2 Compact Home Pressure Washer Review

  • Ideal for domestic situations
  • Don’t emit gas fumes
  • Quieter and lighter than petrol pressure washers
  • Can be used in unventilated areas such as garages and basements etc
  • Generally inexpensive

Disadvantages of Electric Pressure Washers

  • Must be used near a power source
  • Slightly lower power and pressure
  • Suitable for occasional use

Petrol Pressure Washers 

Petrol pressure washers are ideal for larger jobs such as cleaning garage floors, walls of buildings and agricultural machinery.

Since there is no power cord involved petrol pressure washers give greater mobility options.

Petrol units are usually started with a manual cord pull however some units feature an electric starter switch.

Ensure that the correct fuel is used and be aware that over time petrol can degrade and corrosion or the formation of gum and varnish in the fuel system can damage the engine.

To keep petrol fresh and to prevent the formation of gum and varnish you can use a fuel stabilizer.

Also ethanol-free pre-mixed fuels are also available. The mixed fuels also stay better longer ensuring easier starts for your unit.

The instruction manual may instruct you to run the fuel system dry or to top up the tank with a mix of fuel and fuel stabilizer.

Advantages of Petrol Pressure Washers

  • Don’t need an electric power source
  • Able for frequent use
  • Longer Life
  • Stronger power and pressure
  • Takes less time and effort to clean larger areas

Disadvantages of  Petrol Pressure Washers 

  • Heavier and noisier
  • Emits gas fumes to use in ventilated areas only
  • Require more maintenance

Pressure Washer Capabilities 

nilfisk pressure washer reviewPressure washers can be graded from light-duty models to extra-heavy duty models. It is essential to choose the correct type of power washer for the job.

A key factor in determining which pressure washer is suitable for the job is the pressure output in pounds per square inch (PSI) measurement.

Light-duty pressure washers create between 1500 and 1900 PSI and, as the name implies, are suitable for smaller jobs such as cleaning garden furniture and stepping-stones etc.

Medium-duty pressure washers generate between 2000 and 2800 PSI and are ideal for larger floor work such as garages, patios and driveways.

Heavy-duty pressure washers operate between 2900 and 3200 PSI. They are also suitable for larger work including the removal of stains et.

Extra heavy-duty pressure washers create PSI of 3300 and over. Obviously heavy-duty units are great for heavy work including the preparation of surfaces for painting.

Water Flow Rate and PSI 

Though PSI is a very important measurement when comparing pressure washers another measurement to look for is water flow rate which is the amount of water the unit can deliver in an hour.

The higher the combined numbers the more effective your power washer will be.

Pressure Washer Pumps 

Many people forget that the pump is just as important as the engine!

There are three main types;

  1. Wobble pumps are the cheapest type of pump and are not replaceable. Their life expectancy is around 300 hours. When the pump fails you need to buy a new pressure washer.
  1. Axial-cam pumps are much more durable than wobble pumps. Their bearings and oil reservoirs are larger and their life expectancy is 600-700 hours before repair or servicing is needed.

Axial-cam pumps are ideal for domestic use.

  1. Triplex pumps are more efficient than axial-cam pumps and they also have a longer life expectancy. More suitable for commercial applications triplex pumps are generally placed into larger and more expensive pressure washers.

Pressure Washer Nozzles Karcher K2 K4 Pressure Washer Review Clean Car Motor Bike

Petrol pressure washers, and some types of electric models, usually come with colour coded nozzles.

The nozzles are colour coded to ensure that you use the correct nozzle for the job without damaging the underlying surfaces.

  1. Nozzle colour indicated degree of the angle, or the size of the spray fan, of the water.
  1. The wider the angle, or size of spray fan, the less powerful the spray will be.
  1. Concentrate the angle, or spray fan, for a very powerful cleaning solution.

The different coloured Nozzles are coded as follows 

Black – 65 degree spray angle. Used for soap or chemical applications. Once soap or chemicals have been applied to the area a different colour nozzle is needed for deep cleaning.

White – 40 degree spray angle. Ideal for softer surfaces.

Green – 25 degree spray angle for garden furniture etc. A green nozzle may not be included when purchasing a new pressure washer.

Yellow – 15 degree spray angle for a very powerful spray. Ideal for oil stains and stripping paint etc.

Red – 0 degree spray angle for the most powerful spray. This setting can mark concrete so be sure to test in a very discreet area.

Power washer nozzles do wear out over time but thankfully they are easy and cheap to replace.

Pressure Washer Accessories 

There are a number of accessories available to make your cleaning more effective.

These accessories include;

  • Brushes for scrubbing power
  • Extension wands to reach high places easily
  • Angled wands to clean gutters etc
  • Surface cleaners with spinning jets for more effective driveway cleaning
  • Pressure washer chemicals (only use manufacturer approved chemicals)

Using a Pressure Washer

Here are some great tips for using a pressure washer.

Stand solidly on an even surface keeping good balance.

Wear eye protection, Wellington’s and appropriate clothing.

Always turn machine off when leaving it unattended.

Use appropriate nozzle and spray settings for the job. A spray that is too powerful can damage the underlying material (this is especially true for wooden surfaces).

Ensure that there are no people, animals, plants, electrical  fixtures or other power sources where you are directing the spray.

Karcher K4 Pressure Washer ReviewPressure Washer Maintenance

Being an appliance pressure washers need care to life a full life and to operate at maximum efficiency.

Petrol pressure washers need more maintenance than electric pressure washers this includes air filter, oil and spark plug changes. Both types of pressure washer need general inspection and pump inspection.

If the pressure washers are stored in temperatures that fall below freezing steps need to be taken to stop the pump from freezing.

Each pressure washer model will have its own maintenance instructions in the accompanying manual. You are advised to read the user manual thoroughly and to follow the maintenance instructions within.

5 Point Check List For Buying A Pressure Washer

Here is a 5 point check list to make buying a pressure washer easier.

  1. Choose The Type Of Pressure Washer 

Do you need an electric or petrol pressure washer. Remember electric pressure washers are fine for domestic work but for larger commercial jobs you’ll need a petrol pressure washer.

  1. Choose Between Hot or Cold Water Supply 

Cold water is fine for domestic jobs but hot water is great for heavy-duty commercial or farm work.

  1. Choose a Brand 

I’d recommend buying a ‘brand’ pressure washer such as Karcher or Bosch etc.

By buying a brand name appliance you are generally ensuring good after sales customer service and reliable warranty / guarantee coverage.

  1. Choose a Pump Brand 

The pump is on par with the engine in order of importance as it puts the pressure on the water that gives the washer its cleaning power.

For domestic use the best type of pump is an axial-cam pump. All the brands listed in the introduction higher up this page have axial-cam pumps available.

  1. Compare PSI and Water Flow 

Both PSI and water flow were discussed above. The higher the numbers the more powerful the pressure washer will be.

Remember to use the correct PSI for the job as a pressure washer that is too powerful for the job can damage surfaces.

Buying a Pressure Washer 

After you have answered the above 5 questions you are now ready to buy a pressure washer.

We hope that you have enjoyed reading this pressure washer guide. If you have any questions please feel free  to ask either through our contact form or through the comment section below.

The Ultimate Pressure Washer Guide
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The Ultimate Pressure Washer Guide