The honest answer is almost always the K4. The K2 is a light, occasional washer for one small car and garden furniture. The K4 Power Control Flex is the first Kärcher that behaves like a household machine: water-cooled motor, 8 m Flex hose, a gun that shows the pressure step, and enough flow to run a proper patio head.
This page compares the current UK K2 boxes you can buy in the UK right now (Power Control, Home, Classic and Horizontal) with the current K4 Power Control Flex and its Home kit. Specs come from Kärcher. Street prices come from Screwfix, Argos, Very, Kärcher UK and Amazon on 16 August 2026. Some Argos and Very pages blocked or timed out on this check. Those prices are taken from live search snippets and flagged.
If you click through and buy, we may earn a commission.
The rest of the range sits on the Kärcher hub. Cars and paint-safe settings sit on the cars guide. Patio heads sit on the Kärcher patio cleaner page.
Quick picks
The one to buy
K4 Power Control Flex
£199.99 at Screwfix
130 bar, 420 L/h, 8 m Flex hose. The real household step-up from a K2.
Best if the patio is the job
K4 Power Control Flex Home
From about £210
Same K4, plus a T 5. Do not buy a K2 Home and hope the small head will do a green terrace.
Best budget K2
K2 Home / Power Control
£108.99 at Screwfix
110 bar, 4 to 5 m hose, about 4 kg. Fine for one small car. Not a driveway machine.
Cheapest Kärcher still sold
K2 Horizontal / Classic
From about £80 to £90
Same 110 bar class, 3 m hose. Still sold. Buy it only if the job is furniture and a bike.
Comparison table
| K2 class | K4 Power Control Flex | |
|---|---|---|
| Typical UK SKUs | Power Control, Home, Car & Home, Classic, Horizontal | Bare Flex 1.324-302.0, Home 1.324-304.0 |
| Max pressure | 110 bar | 20 to 130 bar |
| Flow | 360 L/h | 420 L/h |
| Area (Kärcher figure) | 20 m²/h | 30 m²/h |
| Hose | 3 m Horizontal / Classic, 4 m Screwfix Home, 5 m on many Power Control kits | 8 m PremiumFlex |
| Motor | 1.4 kW, air-cooled | 1.8 kW, water-cooled |
| Weight | about 4 kg | 11.5 to 12.2 kg |
| Patio head in Home kits | T 1 (small) | T 5 |
| Honest job | One small car, furniture, light tools | Cars, furniture and a normal patio |
| Typical UK price, 16 Aug 2026 | Screwfix Home £108.99. Classic £84.99. Argos Car & Home about £100. Horizontal about £80 to £90 | Screwfix Flex £199.99. Home from about £210 |
Prices checked 16 August 2026. Confirm what is in the box. K2 SKUs multiply. The number is the pump class, not the kit name.
Who should buy which
Buy the K4 if you already know you will wash a car and the slabs, or if you hate short hoses. That is most UK households that are shopping this comparison in good faith.
Buy the K2 if the budget is tight, the only job is one small or medium car plus light furniture, and you will not also take on a mossy drive. Accept the short hose and the air-cooled motor.
Do not buy a K2 Home as a patio machine. The head in that box is a T 1, not a T 5. Fine for a tiny yard. Thin on a green terrace. If the patio is the main job, buy a K4 Home kit.
Skip both if there is no outdoor socket or no tap. Start with the cordless guide.
Kärcher K4 Power Control Flex
The real household Kärcher
- Buy: Screwfix £199.99 · Amazon listing (page 503’d this check) · B&Q listed at £209, diy.com was down this check · Kärcher UK official around £220
- Pressure / flow: 20 to 130 bar, 420 L/h
- Hose: 8 m PremiumFlex
- Motor: 1.8 kW, water-cooled
- In the box (bare Flex): G 160 Q Power Control gun, Vario Power lance, dirt blaster
- Who it is for: anyone who wants one machine for cars, bikes, furniture and a normal patio
This is the step-up. 130 bar with a twist-to-adjust Vario is the useful UK class for paint and stone. The LED on the gun shows the step, so you are not guessing. Eight metres of Flex hose walks a family car if you park the trolley at a corner. The water-cooled motor is quieter and happier in a long session than the K2’s air-cooled unit.
The dirt blaster is for stone, not lacquer. Plug ‘n’ Clean sits in the body if you want shampoo through the lance. A dedicated foam jet is the better car accessory, around £30 to £33. Paint distance and foam order sit on the cars page.
If the drive is long and filthy, the next step is a K5, not a second K4. That comparison is on K4 vs K5.
If you already know you want more than a K5, that is K5 vs K7.
Skip it if you only rinse one small car a few times a year and you will never touch the slabs. The K2 will do that for about half the money.
Kärcher K4 Power Control Flex Home
The K4 if you also want the patio head
- Buy: Amazon Home listing (UK buy-box not locked this check; PriceSpy from £209.99) · Viking Direct £219.99 excluding VAT on a 2+ deal · Kärcher UK Home
- Part number: 1.324-304.0
- In the box: K4 Flex, T 5, 1 L stone cleaner, Vario, dirt blaster, 8 m Flex hose
- Who it is for: households that need a washer and a proper patio head
Home on a K4 means a T 5. That is the everyday 280 mm hood, K2 to K7. It is not the small T 1 that ships in a K2 Home box. Do not then buy a second T 5.
A separate T 5 is from about £55. If the bare Flex is £200, a Home kit at about £210 to £245 is a small premium. Shop the live total. Full head notes sit on the patio cleaner page.
Skip it if you already own a working K4. Buy the head on its own.
Kärcher K2 Power Control and Home
The budget Kärcher, if you are honest about the job
- Buy: Screwfix K2 Home £108.99 · Argos Power Control Car & Home about £100 (was £170; live page timed out this check, search still shows £100) · Very Power Control Home £129.99 on search snippets, page blocked this check · Kärcher UK Power Control Home
- Pressure / flow: 20 to 110 bar, 360 L/h
- Hose: 4 m on the Screwfix Home box, 5 m on many Power Control kits
- Motor: 1.4 kW, air-cooled
- Weight: about 4 kg
- Who it is for: one small or medium car, light furniture, a buyer who will not also take on a mossy drive
110 bar is enough to wash a car if you foam first and stay on the Vario’s wide setting. It is not enough to pretend this is a patio machine. The short hose is the daily frustration. You will drag the trolley around the car. The air-cooled motor is louder and less happy in long sessions than the K4.
K2 SKUs multiply: Power Control, Home, Car & Home, Classic, Horizontal. Same 110 bar class, different hose and extras. Screwfix titles the Home box Karcher K2 Home. That kit includes a T 1 and 0.5 L patio and deck detergent, not a T 5. Fine for a balcony or a tiny yard.
Treat the K2 as a first machine. If you already know you will do the drive twice a year, buy the K4. Saving £90 today and replacing it next spring is the expensive route.
Skip it if you have two cars, a long hose run, or you want a gun that shows the pressure step on an 8 m Flex hose.
The K2 cartons in full sit on the K2 review.
Kärcher K2 Horizontal and Classic
Still sold. Still a light machine.
- Buy Horizontal: Kärcher UK still listed (part 1.600-935.0). Official range tiles have shown £89.99. Comparison sites on this check ran about £80 to £90.
- Buy Classic: Screwfix K2 Classic £84.99
- Pressure / flow: 110 bar, 360 L/h
- Hose: 3 m
- Who it is for: bikes, tools, a chair, a buyer who will store it on a shelf
The Horizontal is the compact, low box. The Classic is the small upright. Both are the same 110 bar class as Power Control. The hose is the tell: three metres. That is a bike and a bench, not a car you walk around. Screwfix’s Classic box includes a single spray lance, a dirt blaster and a 3 m hose.
Refurbished Horizontal stock appears at the official outlet from time to time. The outlet page was not in stock on this check. Do not hunt a refurb to “save” your way into a patio machine. If the job has grown past furniture, the K4 is the buy.
Skip it if you will wash a car every weekend. The hose will annoy you on day one.
Cars, patio and the T 1 mistake
A K2 will wash a car. Stay on the wide Vario, keep your distance, foam first. It will not match a K4 for a weekly family wash. The short hose is why. You park, move, park again. The cars guide is written around the K4 for a reason.
A K2 will spin a T 5 if you buy one separately. It will feel thin on a green terrace. 110 bar and 360 L/h move the head. They do not strip a winter of algae the way a K4’s 130 bar and 420 L/h do. K2 Home does not include a T 5. It includes a T 1. Shops still sell that box as a patio kit. It is a small-yard kit.
If the patio is the main job, buy the K4 Home. If you already own a K2 and the slabs have gone green, the honest upgrade is a K4, not a £55 head on a weak pump. The patio cleaner page has the T 5 and T 7 Plus prices. The T 7 Plus is K4 to K7 only. A K2 cannot run it.
How to choose
- One small car, furniture, tight budget, no slabs. K2 Home or Power Control. Accept the hose.
- Furniture and a bike only. Horizontal or Classic, if the price is about £80 to £90.
- Cars and a normal patio. K4 Power Control Flex. Add Home if you do not own a T 5.
- Long or filthy drive. Skip this page. See K4 vs K5.
- No socket or no tap. Cordless. Not a bigger K2.
Power Control on a K2 is a nicer gun than Classic, not a different pump class. Flex on a K4 is the hose you want. Home means a patio head. On a K2 that head is small. On a K4 it is a T 5.
Register the machine if you want the extra Kärcher years on top of the standard two. Terms apply. First-use setup, nozzles and frost drain-down are on how to use a pressure washer. Other reviews sit on the reviews index.
FAQ
Is the K4 worth twice a K2?
If you will do cars and stone, yes. The K4 is not twice the bar. It is a longer hose, a water-cooled motor and a patio head that actually matches a UK terrace. If you will only rinse a Fiesta four times a year, no.
Can a K2 clean a driveway?
Slowly, and only if the dirt is light. A green, neglected drive is a K4 or K5 job. Putting a T 5 on a K2 does not turn it into a K4.
Is the K2 Horizontal still sold?
Yes. Kärcher UK still lists it. Screwfix’s live compact alternative on this check is the K2 Classic at £84.99. Same 110 bar class, 3 m hose.
Will K4 accessories fit a K2?
Most Home & Garden bayonet lances and the T 5 will clip onto a current K2 gun. The T 7 Plus will not. Very old guns can need adaptor 2.643-950.0.
Should I wait for a K2 sale instead of buying a K4?
Only if the job is genuinely light. Argos has had Car & Home around £100. That is a good K2 price. It is not a reason to take a 4 m hose onto a family drive.