Karcher Pressure Washers: The Range Compared and Reviewed
The Karcher range of pressure washers is one of the best known in the UK, with their distinctive yellow branding and wide range that covers all budgets and uses.
There are currently 11 models in the Karcher pressure washer range, from the K2 Compact through to the K7 Premium Full Control Plus Home, with prices ranging from under £100 to around £500 for the top of the range models.
Within the range are 4 distinct “K” families of pressure washer, each one having a different level of performance. Then within each K family, there are different product types such as Compact, Full Control and Full Control Home.
How to choose your ideal Karcher pressure washer: first choose the performance level (K family) then choose what features and accessories you require from the family models.
First, let’s take a look at the differences between the K families.
Best Selling Karcher Pressure Washer Models
| IMAGE | PRODUCT | |
|---|---|---|
Best seller  | Karcher K4 Full Control
| VIEW ON AMAZON → |
 | Karcher K2 Full Control Home
| VIEW ON AMAZON → |
 | Karcher K2 Compact
| VIEW ON AMAZON → |
 | Karcher K2 Full Control
| VIEW ON AMAZON → |
K2, K4, K5 and K7 Pressure Washers Compared
| K2 | K4 | K5 | K7 | |
|---|---|---|---|---|
| Motor power rating (kW) | 1.4 | 1.8 | 2.1 | 2.8 |
| Motor type | Air-cooled | Water-cooled | Water-cooled | Water-cooled |
| Max Pressure (bar) | 110 | 130 | 145 | 180 |
| Max flow rate (litres/h) | 360 | 420 | 500 | 550 |
| Area coverage (m2/hour) | 20 | 30 | 40 | 60 |
The main difference between the K families is the power (and type) of pump motor, which in turn gives different results in terms of maximum spray pressure, flow rate (measured in litres per hour) and the typical size of the area you could cover in an hour (square metres per hour).
K2
Let’s start with the budget K2. This has a 1.4 kW air-cooled motor that can provide a maximum pressure of 110bar. The flow rate is 360 litres per hour and you are looking at being able to cover roughly 20 square meters per hour. The K2 range is a good budget pressure washer for more basic uses such as smaller patio cleaning and car washing.
The K2 is available in Compact, Full Control, Full Control Home and Premium Full Control Home models. All K2 models have a 4-metre hose (except the Premium Full Control Home that has a 6m hose) which is okay but will mean you are moving the pressure washer around when working on larger areas.
Luckily, the K2’s are fairly light, weighing between 4.1 and 4.6kg. The bottom of the range K2 Compact is the only model without wheels and a carrying handle. While this does affect portability it also means that its easier to store (due to its smaller size).
K4
Next is the K4 family, these have a more powerful 1.8 kW water-cooled (for better efficiency and reliability) motor. Maximum pressure increases (vs K2) by 18% to 130 bar and flow rate is up 17% to 420 litres per hour. The increase in flow rate allows you to cover 50% more area than the K2 at 30 square meters per hour.
As with the K2, the K4 is available in Compact, Full Control, Full Control Home and Premium Full Control Home models.
All K4’s have a long 6-metre hose but the weight is up significantly versus the K2, ranging between 10.7 and 11.9 kg. The K4 is more suitable for larger patio/decking areas or for shifting more stubborn dirt or grime.
K5
The K5 starts getting into professional territory, both in terms of cost and specification. Motor power is up to 2.1kW (again water cooled). Compared to the K4, maximum pressure is up 12% to 145 bar and flow rate increases to an impressive 19% to 500 litres per hour. More impressive is the increase (up 66%) in area coverage from 30 to 50 square meters per hour.
The K5 is only available in Compact Home and Premium Full Control Plus Home models.
Both K5 models feature a much longer 8m hose (double that of the K2 basic models). Weight does start to increase though with the K5 Premium Full Control Plus Home weighing 13.6kg, luckily it’s on wheels.
K7
At the top of the Karcher pressure washer range is the K7, which is only available as a Premium Full Control Plus Home model. At around £500 retail, the K7 is an expensive bit of kit so is probably more suitable for professionals or for those with very large gardens.
The power rating of the motor is 2.8kw (so double that of the K2) which provides a maximum pressure of 180 bar, which is up 24% compared to the K5. Flow rate increases 10% versus the K7 to 550 litres per hour and typical area usage increase 20% to 60 square meters per hour. Hose length on the K7 also increases to 10m.
The K7 also has an increased maximum water feed temperature of 60 degree C compared to 40 degree C on all other models. At this price point and high specification, it really is a choice for professional use (such as car or garden cleaning businesses).
Now that (hopefully) we’ve understood the difference between each K family, let’s take a look at the different models within each K range.
What’s the difference between each model?
Compact – these model versions are available in the K2 and K4 ranges only. These are the basic versions with no additional cleaning kit, basic spray guns and lances. The detergent addition is via a suction tube from a separate bottle.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
Compact Home – only available on the K5 (its the cheapest of the two K5’s). Again a more basic version with standard spray gun/lances. Has suction detergent addition. This is a cheaper way to get the K5 power but this version misses out on a lot of kit.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
Full Control – available on the K2 and K4. The change here is the addition of the “Control” spray gun. The K2 has a G120Q version and the K4 a G145Q. Detergent application on the K2 is via suction but the K4 steps up to “Plug & Clean”.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
Full Control Home – available on the K2 and K4 and essentially the same as the Full Control but includes a “Home” kit. The K2 includes a T150 patio cleaner, 0.5l 3-in-1 Patio and Deck Cleaner while the K4 includes a T350 patio cleaner, 1l 3-in-1 Stone and Façade Cleaner.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
Premium Full Control Home – again, available only on the K2 and K4 models. The difference between the K2 Full Control Home and Premium version is the addition of a longer 6m hose (versus 4m) and detergent addition via tank rather than a suction tube.
The only difference between the K4 Full Control Home and Premium version is the addition of a high-pressure hose reel to keep the hose tidier and easier to manage on the pressure washer.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
Premium Full Control Plus Home – only available on the high-end K5 and K7 models. This version features the top end G180Q Full Control Plus gun and the 3-in-1 MultiJet. As this is a “Home” version it also includes the cleaning kit. The K5 comes with the T350 patio cleaner, 1l 3-in-1 Stone and Façade Cleaner and the K7 includes the T450 patio cleaner and 1l 3-in-1 Stone and Façade Cleaner.
Last update on 2023-12-08 / Images from Amazon Product Advertising API
In this section, we have mentioned different spray guns, detergent systems and lances. Lets now take a look at what these are.
Karcher Pressure Washers – Key Features
Spray Guns & Lances
- Standard Quick Connect gun – a basic trigger spray gun included on the K2/K4 Compact and K5 Compact Home.
- G120Q High-pressure gun – included on the K2 Full Control, Full Control Home and Premium Full Control Home models. Slightly different “open” version of the standard gun
- G145Q Full Control Gun – included on the K4 Full Control, Full Control Home and Premium Full Control Home. This is a more sophisticated spray gun that works in combination with the Vario Power spray lance. The lance can be twisted to three different power setting – Soft, Medium and Hard and once you have done this a corresponding LED light is shown on the trigger display. There is also a Mix setting for use when detergent is added.
- G180Q Full Control Plus Gun – included on the Premium Full Control Plus Home versions of the K5 and K7. This is a fairly sophisticated bit of kit that is used in combination with the 3-in-1 Multi Jet spray lance. So rather than changing lances, this one lance can switch between flat stream, rotary (for shifting stubborn dirt) and detergent nozzle settings. These settings are then shown on a large LCD display on the control gun, plus the control gun also features plus/minus buttons for changing the pressure setting and detergent dosing levels.
- Dirt Blaster Spray Lance – this is included on all models except the K5/K7 Premium Full Control Plus Home (as these have the 3-in-1 multi lance). This lance uses a rotating fine jet that is useful for cleaning more difficult to shift dirt (for instance, green moss on patios).
Detergent systems
Karcher offers 3 main types of detergent system on their pressure washers:
- Suction – this is the more basic version and relies on the detergent being fed into the pressure washer via a suction tube. This means that you have to place the bottle (very) near to the pressure washer. Plus, you have to move it every time you need to move the pressure washer. So if you plan on using a lot of detergents (say for car washing) then its best to pick a model with a longer hose so you can keep the pressure washer in place. The K4 and K5 have longer hoses than the K2. In reality, models with suction delivery are intended for occasional detergent use only.
- Tank – only available on the K2 Premium Full Control Home. This is a step up from the suction system as your pour the detergent into a reservoir tank at the base of the pressure washer. Much easier to use than the basic suction system.
- Plug and Clean – available on all K4 Full Control (including Premium and Home) models and the K5/K7 Premium Full Control Plus Home models. The detergent bottle is simply connected directly to the pressure washer so this is by far the best option if you plan on using a lot of detergent.
Home cleaning kits
There are 3 different cleaning kits supplied with “Home” versions of Karcher pressure washers.
- K2 Home models – includes T150 patio cleaner, 0.5l of 3-in-1 Patio and Deck Cleaner. The T150 is the basic patio cleaner.
- All K4 and K5 Home models – T350 patio cleaner, 1l of 3-in-1 Stone and Façade Cleaner. The T350 features rotary pressure adjustment control and handles for use when vertical cleaning (i.e. walls or garage doors).
- K7 Home model – T450 patio cleaner, 1l of 3-in-1 Stone and Façade Cleaner. The T450 is wider than the T350 and additional features include an angled design and foot operated jet spray for getting into hard-to-reach corners. It also has a mesh protection grid inside the head that allows you to clean gravel and stone areas without disturbing the loose stones and chips.
The patio cleaning heads are a useful tool as they prevent dirty water from spraying back up walls or windows when cleaning dirty or moss-covered patios or decking.
Best Selling Karcher Pressure Washer Models
If you are stuck trying to choose the best Karcher model for you, then below is a comparison of the Top 4 current best selling Karcher pressure washer models:
Karcher K4 Full Control – a decent step up from the basic K2 in terms of motor and maximum pressure and flow rate. As its a “Full Control” model it features the G145Q Full Control Gun which shows the setting of the Vario Spray lance on an LCD screen. Has a reasonable 6m hose and the Plug and Clean detergent system. The “Home” version would add the T350 patio cleaner (with adjustable pressure) whereas the Premium version also includes a high-pressure hose reel.
Karcher K2 Full Control Home – has the lower spec “K2” motor but still suitable for most garden, patio and car cleaning duties. This “Full Control” version features the spray lance with adjustable pressure settings. Also included with the “Home” model is the T150 patio cleaner. This is the more basic of the patio cleaners but still a good addition. This is not the top of the K2 range (that’s the Premium Full Control Home) so the hose is only 4 metres on this version and detergent addition is via a suction tube.
Overall, this is a well-equipped pressure washer for around £100. Starting to show its age a bit though compared to some of the newer (higher spec) models.
Karcher K2 Compact – this is the bottom of the Karcher pressure washer range so lacks a lot of features found on other models. This model does not come with wheels or an extendable handle. On the plus side though, this is a very well priced pressure washer that is often on sale for less than £100. Also, because it’s quite compact it’s easier to store where space is at a premium.
Karcher K2 Full Control – This is essentially similar to the K2 Full Control Home model mentioned above but without the patio cleaner (and cleaning detergent). This version is a little cheaper than the “Home’ version but we would spend the extra to get the patio cleaning tool.
Make sure to also check out how Karcher pressure washers compare to Bosch.
