This smart Karcher pressure washer made my patio and garden look brand new again – it's a cleaning powerhouse that blasts away winter grime effortlessly

With the cold, dark winter months behind us, my attention is well and truly focused on cleaning up our act outside. By this, I mean that the patio needs a blast, kids' toys need a rejuvenation, and the car needs a hose down. The most efficient (and fun) way to achieve this? Pick up the Karcher K7 Premium Smart Control, RRP £599.99, £439.99 on sale right now on Karcher.

I tested it over a couple of weeks, taking full advantage of the spells of spring sunshine. I found that it had the power to shift stubborn grime and enough length in the cable to get (almost) full access around the sides of my house from the outdoor power socket. It has easily got to be one of the best pressure washers on the market.

You can expect the usual German build quality with Karcher products, and the K7 Premium Smart Control is no exception – it's a solid piece of kit, designed with a retractable handle, hose and cable tidy. It can be customised with complementary accessories such as the Power Scrubber PS 30 surface cleaner and FJ 6 foam nozzle for more targeted cleaning, but these are an optional extra that can cost an additional £20 - 50 depending on the tool you opt for.

From unboxing and pairing the pressure gun to Bluetooth and using it on our outdoor equipment, I've given this pressure washer a run for its money. It'll cost you circa £600, so I've found out if it's worth it.

Specifications

• Model number: K7 Premium Smart Control
• Dimensions (cm): H66.9 x W33 x L45.9
• Voltage: 230 - 240
• Wattage: info not available
• Weight: 18.1kg
• Cable length: 5m
• Hose length: 9m
• Pressure (max): 20 - max. 180 / 2 - max. 18
• Flow rate (max): max. 550
• Nozzles: 2
• Accessories: 3-in-1 multi-jet spray

In a nutshell

The Karcher K7 Premium Smart Control is a prime example of the quality and performance that one would expect from a German brand. Some standout design elements include a telescoping (aka retractable) transport handle, hose holder, accessory compartment net and smart control high-pressure gun.

That pressure gun can be powered-up by 2x AA batteries to select pressure and detergent dosing levels. You can toggle through up to six pressures or "Boost" for max pressure. The greater the pressure, the louder the noise. And it was already a LOUD pressure washer – I recorded 82dB on a decibel meter reader app on my iPhone.

Noise aside, it did a fantastic job cleaning our patio, garden furniture and outdoor kids' toys; dirt and grime was blasted away with a zig-zag pattern. It wasn't so great at cleaning up the car tyres or trim around our side door, though.

It comes with a 5-year guarantee (plus an extra year if you buy direct from Karcher) so you might decide it's worthwhile the investment.

Karcher K7 Premium Smart Control: Unboxing and delivery

My first impression of the Karcher K7 Premium Smart Control was that it was big. Huge, in fact. I felt a little overwhelmed by the delivery box that was plonked on our porch, and it took some brute strength to haul it into the hallway.

Inside the box was no plastic packaging (hurrah) and some neat compartments to house the 3-in-1 multi-jet spray and high-pressure gun. The main bulk of this pressure washer was as one unit, which, I thought, would make set-up easy. How wrong I was.

The instructions are dizzying. For example, a diagram of the K7 Premium Smart Control is on pages 2 - 3 of the instruction booklet, yet a description of the device is on page 9. Furthermore, pages 4 - 6 were a series of illustrations to demonstrate the assembly instructions to get the pressure washer working. This was as clear as mud.

However, after some trial and error, I managed to get all the hardware together, but you can also sync to the Karcher Home & Garden app via Bluetooth for device management and servicing, and control of the pressure washer. I found that the easiest way to do this was to download the app and then scan the QR code printed on a separate piece of cardboard found inside the delivery box.

Personally, I preferred to use the K7 Premium Smart Control physically rather than through my phone. I imagine that it'll be useful to get cleaning updates and maintenance advice as the weeks turn into years of me taking ownership of it, though.

What I did find more useful was installing 2x AA batteries in the pressure gun so I could increase or decrease the pressure or boost. The battery compartment can be accessed by pushing on a couple of buttons on either side of the handle. Just be sure to remove the protective film layer from the handle, which is in place upon delivery.

Who will the Karcher K7 Premium Smart Control suit?

This is a serious bit of kit, and you get what you pay for. It's a quality machine which is easy to use, but not straightforward to put together. Once you get over the set-up hurdle/s then it would be a great choice for those who are looking to get their first pressure washer.

For what it is, it's also fairly compact and doesn't take up too much space in the shed. The pressure is also fantastic for shifting surface-level grime, but for ground-in stains, it might make matters worse.

Using the Karcher K7 Premium Smart Control

Despite the ropey instructions which didn't give me any confidence in my set-up abilities, I was relieved that not only did I get the Karcher K7 Premium Smart Control to work, but I could also use it without being too overwhelmed by its everything.

It's a large device with some big attachments and smart abilities, and it's LOUD. I recorded 82dB on a decibel meter reader app on my iPhone, which is equivalent to car noise. It's also heavy (18.1kg) to lift, so I used the retractable handle as much as I could across flat surfaces.

How did the Karcher K7 Premium Smart Control perform?

Patio

I first used the Karcher K7 Premium Smart Control pressure washer to clean the patio, which wraps around the back and side of our house. It doesn't get any direct sunlight, so the black pavers are prone to growing moss and algae. I shamefully hadn't cleaned the patio before, and it had been left for almost two years. This means that there was a lot of grime to shift.

I set the flat jet nozzle to a "hard" pressure level. This is the most suitable for stone terraces, metal surfaces and garden utensils. I then worked the nozzle in a zig-zag pattern across the surface of the patio. It took almost one hour to shift, but I didn't notice the time whizz by, and I found it immensely satisfying to see the end result.

I stretched the 5-metre power cable and 9-metre hose to their limits. I managed to reach our side door, but there was an area of patio down the side of our garden that I was unable to reach without plugging into a socket inside the utility room. This length of power cable will be long enough for most households, I'm sure, but it fell a little short for me, which was a little frustrating.

Garden furniture

Our one and only garden chair (sad times) had turned green. It's white underneath. It was covered in algae and mud, and I really didn't fancy sitting on it to enjoy a brew in the spring sunshine.

The pressure of the water pushed the chair back and across the patio. I used my other hand to hold it down so that I could clean it. I moved the high-pressure gun in a zig-zag position across the seat, back and arms of the chair to reveal the original white colour.

Kids' toys

Last year, the kids' toys were pink, but this year they were green with algae. Nice (not). I really didn't like the idea of them playing with the toys in their current state, so I put the K7 Premium Smart Control pressure washer to work.

The force of the pressure pushed the toys across the patio, so I used my other hand to hold down the rocking horse and outdoor table and chair set to clean it. Moving the high-pressure gun in a zig-zag position across the sludge budged it. Within a matter of minutes, I was seeing pink and red again, on all the toys.

Car tyres

Next, my husband gave cleaning the car tyres a go. He paid particular attention to the alloys. These haven't been cleaned in an embarrassingly long time. So long, in fact, that I can't remember. They were thick with soot and mud.

Whilst the K7 Premium Smart Control busted the majority of dirt from the alloys, we were still left with some marks and stains that only a sponge and some elbow grease could lift.

What's the Karcher K7 Premium Smart Control like to clean and store?

Looking through the instruction booklet of the Karcher K7 Premium Smart Control, I see a lot of "DANGER", "CAUTION", and "ATTENTION" in the sections for Storage and Care and Service. This is in relation to the weight (be aware), frost (make sure the device is empty) and electric shock (make sure it's switched off). There is also mention of a "sieve" which is located behind the water connector. This is to be cleaned under running water.

The high-pressure gun can also be used with non-chargeable or rechargeable AA batteries. These are to be replaced when required and disposed of in accordance with statutory provisions.

I stored this pressure washer in our shed, but it can be stored anywhere where it is under cover. The hose can be wrapped around the on-board storage, and the power cable can be neatly tucked into the accessory compartment net. If you have accessories to put in this net, then just ensure that the power cable isn't going to be a trip hazard and is out of harm's way.

How does it rate online?

There are some mixed reviews of the Karcher K7 Premium Smart Control online, but overall, customers have awarded it 4-out-of-5 stars. Many users have praised its effectiveness on various surfaces and its durable construction. They note that it offers a strong cleaning performance with adjustable pressure settings and smart app integration.

However, not everyone has had such a good experience with the K7 Premium Smart Control. A few customers have commented that it makes a "humming" noise when switched on, and it stopped working, whereas others are unimpressed by the level of customer service they received.

Should you buy the Karcher K7 Premium Smart Control pressure washer?

I enjoyed using the Karcher K7 Premium Smart Control, and I found it immensely satisfying. It's perfect for cleaning the patio, garden furniture and large kids' toys that live outside. Whilst it is a large machine which is a lump to move, overall you won't be disappointed in the build quality and performance output.

However, it wasn't so good at removing the more stubborn grime that we had on the car alloys and around the windows. I also found it really LOUD, so I really felt for our neighbours who were quietly pottering in their own gardens.

It's not widely available, but I've found it on the Karcher website and reseller sites such as OnBuy. At the time of writing it was £439.99 when you buy direct from the brand, which, yes, is an investment, but it'll be the only pressure washer you'll ever need.

How does the Karcher K7 Premium Smart Control compare to other pressure washers?

So, hands up, I haven't used a pressure washer before, making the Karcher K7 Premium Smart Control my first. However, I've looked at other pressure washer reviews written by my product reviewer pal Linda Clayton, who highly rates the Stihl RE 120 Plus, £432 at Amazon.

The Stihl, also a German brand, offers a slightly lower 135 bar pressure and 2200W motor than the K7 Premium Smart Control, but it comes with more accessories. It's also more affordable; £432 when it's NOT on sale. Linda loved that it is easy to use, and it just feels robust and well-made.

If I'm way off your budget and you're looking for something half the price, then the Greenworks G40 could be a good fit. Linda also put this one to work, who reported that it is well suited for cleaning patios, driveways, cars, and similar outdoor projects, although she'll never rate the build quality (it’s the main reason it was awarded a 3.5 score overall).

About the review, and our reviewer

Jennifer Oksien

Jennifer (Jen) is a freelance product reviewer and has tested many products over the years, including home tech, garden tools and mattresses. She lives in Bath with a generous wrap-around garden to one side, which demands regular attention. The Karcher K7 Premium Smart Control pressure washer was used to clean up the patio, scrub up the kids' outdoor toys and make the car tyres shine again. Her husband also used it (he couldn't help it), so it's debatable exactly who cleaned what, but they were ultimately both impressed.