Pressure Washer Buying Guide

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If you have a car or home then a pressure washer can be a great help! By using high pressure water it can easily and quickly remove dirt and grime from home driveways and patios. They are also great for car and bike cleaning.

However when looking for a Pressure washer to buy there are several things you will want to consider.

Cleaning ability

When looking at pressure washers you’ll be faced with a few technical details and jargon. The most important for cleaning ability is pressure usually measured in Bar and Water Flow Rate measured in litres per hour (l/h)


The pressure rating is an indication of how high the cleaning performance will be, while bigger can be better it does need to fit with the desired usage. Typically home pressure washers start at 110 Bar and go up to 180 Bar. If you are just clearing of fresh dirt from Cars or bikes then a washer rated at 110Bar will be fine. However, if you’ve got driveways and patios with years of dirt and grime then you’ll want something rated above 140Bar. That will give it enough power to really push out the years of dirt. Most manufacturers will quote the Maximum Pressure their machines can go to before the pump protection system (usually a safety valve of some sort kicks into action), while it is a slightly artificial number it does give you a good way to compare the different jet washers. So if you are looking at the Karcher K2 Full Control Pressure washer; its’ 110 Bar Rating it means it could hit 110 Bar pressure (usually when first turned on) but realistically it can not hold this pressure during sustained usage. There are some manufacturers that give a “Bar rated pressure”. This is a somewhat more truthful number as its close to the average pressure you can expect when using the machine. Unfortunately, manufacturers providing this is the exception rather than the rule as the mostly want you seeing the biggest number possible. What does this mean for you? Ideally, when comparing washers you would use the ‘Bar rated’, but since the majority only proved the Max Bar, just keep in mind what you end up with will not achieve that during constant usage. As an example, both the Nilfisk C110 and Karcher K2 pressure washers have a max bar rating of 110, but neither will keep that pressure during a typical cleaning session, but you can be sure they will both have a similar real pressure of around 80-90 Bar.

Water Flow Rate (litres per hour)

If Bar tells you how powerful the cleaning ability is, the l/h rate tells you about its rinsing ability. A higher number here as the rating suggests, means more water will be used when cleaning and the more water you spray onto something the more dirt will be rinsed away. The entry level washers start at 360 l/h and the top of the range Karcher K7 Full Control hits 600 l/h. A question that has come up a few times is: If 2 pressure washers have the same Max Bar Pressure Rating, but different flow rates which one delivers the best cleaning action? The answer is the one with the higher Flow Rate. As it means there will be more water being pushed over the surface you are cleaning at the same pressure.


By now you should have a feel for how much pressure your pressure washer should produce, based on how you plan on using it. But what type of motor is going to produce that power? The cheaper machines will generally use universal brush motors. These have a few advantages: they are light and cheap. On the downside, they are noisy and have a typical total run time of 10-15 hours before kicking the bucket. Now that sounds low but, if you spend 30 minutes using the pressure washer whilst cleaning your car, 8 months a year. Then that’s a yearly usage of 4 hours. So one of these units could give you up to 4 years of service. Indeed I have a neighbour that just uses his for cleaning their mountain bike and it’s 7 years old and still going strong. On the other hand, if you spend 1 hour cleaning your driveway and patio every week, then you’ll be lucky to get 6 months out of the machine. In this case, you’ll want one with an Induction Motor. The brushless induction motor is the best choice for anyone wanting to use the pressure washer frequently or for extended periods. And it’s the standard on all Nilfisk Pressure washers from the C130 onwards and Karcher K4 and up. Induction motors are quieter and have a higher life expectancy (up to 100 hours). To even things out, they are heavier and more expensive. So if you need to lift or carry the washer to use or store it keep this in mind.


The pump is just and important as the motor. Generally speaking, the motor powers the pump and the pump pushes the water out so having a long lasting durable pump is important. The most important thing to keep in mind is that some of the cheaper machines use plastic pumps. If you are looking at a universal motor then a plastic pump won’t be a big issue as the motor is likely to burn out before the pump. But some brands produce machines with Induction motors and plastic pumps – this allows them to advertise with an induction motor, but is a bad combination and should be avoided. If you are getting a pressure washer with an induction motor then make sure it has a metal pump. Most use aluminium, which is good and does its job of avoiding overheating which can happen with the plastic ones. But the top of the line home pressure washers will use Brass Pumps. they last longer than aluminium pumps and won’t suffer corrosion when detergents are passed through them. In all likely hood unless you are looking at paying a lot for your pressure washer you’ll get an aluminium pump. Most manufacturers have solved the issue of pumps being destroyed by cleaning chemicals by having the chemicals added on the way out of the machine. If you get a machine with an aluminium pump, make sure chemicals are added on the way out of the machine, not before it hits the pump.

Hose length

If you don’t want to be constantly stopping to move the machine then make sure you have a nice long hose. 6m+ is a good starting point if you are cleaning your car, anything shorter and you’ll have to stop and move the machine to get all around the car. You can get extension hoses, but they aren’t cheap. So it’s usually better to buy a slightly higher specification machine with a longer hose then a lower spec machine and hose extension.

Other points

Auto stop/start: Make sure the machine has and auto stop feature. This means then when you stop using it the motor stops running. Some cheaper machines just use an overflow/ bypass valve. This leaves the motor running, adds workload the the pump and can more easily lead to a plastic pump overheating.

Static Water Source: If you are planning on using anything other than a normal garden tap (e.g. a water butt or pond), make sure the pressure washer can handle it. Not all can and those that do, require a special suction hose attachment.

Karcher K2s: Karcher have a wide range of K2s: K2 Compact, K2, K2 Premium and K2 Full control and it can be a little daunting when faced with all these, so what is the difference? It’s just the housing and hose length. They all have the same motor and same pump and consequently same cleaning ability. Building up from the cheapest:

  • The K2 Compact is the basic home pressure washer Karcher offer, with a max of 110 Bar it’s powerful enough to clean a car or bike. The universal motor and plastic pump won’t stand up to years of constant use but are fine for occasional shorter bursts of usage. Its’ 4-metre hose is just long enough for smaller jobs, but I would think about an extension hose or higher spec machine if it is to be used for frequent car cleans or larger paths.
  • Karcher K2: It’s the same machine but with a handle and wheels.
  • Karcher K2 Premium: Same as the K2, but with an extra bit of black plastic at the bottom to make it look nice and has a 6-metre hose.
  • Karcher K2 Full Control: Again the same motor and pump but the body has had a face lift for 2017. Also, has a Telescopic handle.

So What pressure washer would I buy in 2017?

It does depend on what you are planning on using it for; if you are just looking a the occasional cleaning of a bike or car then I’d happily go with either the Karcher K2 compact (unless you need wheels or the longer hose) or Nilfisk C110. The Nilfisk comes with a 5-metre hose and is usually priced the same as the K2 Compact. So for a smaller machine it would be my choice.

But in terms of best value for money, it would be the Nilfisk E140 or Karcher K4 Full Control. Both have induction motors and metal pumps so should last for years with proper care and everything the average home needs. These are both so similar it would come down to what is currently on offer.

There are bigger and more powerful machines but for most ‘normal’ home usage the Karcher K5, Nilfisk P150 or Karcher K7 are more than you would need. But if you have a large patio, loads of brickwork or a number of vehicles and caravans you want to clean regularly. Then these are worth looking at. Do keep in mind the larger motors and pumps do add to the weight. The K4 Full control weighs 11kg and the K7 Full Control 18kg. The Nilfik Profesional P150 is the heaviest at 26kg.

Best Places to Buy

Check out the retailers below for any current discounts they may have on pressure washers:



Robert Dyas


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