Buy the Kärcher K4 Power Control Flex if you have a tap, a 13A socket, one or two cars and a normal UK patio. This page answers whether you should take this K4 home, which carton to pick, and when to walk away. The class step up is K4 vs K5. The rest of the yellow range sits on the Kärcher hub.
It is not a lab test. Specs come from Kärcher. Street prices come from Screwfix, B&Q, Amazon, Viking, PriceSpy and Kärcher UK in August 2026.
If you click through and buy, we may earn a commission.
The Flex (1.324-302.0) is the default household buy in the 130 bar class. From about £200 it is the Kärcher most UK homes should start with. The Flex Home box (1.324-304.0) is the same pump plus a T 5 if the patio is part of the Saturday. It is not a K5 for a long green drive. It is not a K2.
Paint-safe settings sit on the cars page. A long plot is the driveway guide. Brand-agnostic mains picks sit on the electric pressure washer page. If £200 is more than you will spend, the budget shortlist is the price-cap page, and K2 vs K4 is the class step below. First-use setup and frost drain-down are on how to use a pressure washer.
Quick picks
The one to buy
K4 Power Control Flex
From £200
130 bar, 420 L/h, 8 m Flex hose. The Kärcher most UK households should start with.
If the patio is the job
K4 Power Control Flex Home
From about £210
Same K4, plus a T 5 and stone cleaner in the box. Do not then buy a second head.
Specs
| K4 Power Control Flex | K4 Power Control Flex Home | |
|---|---|---|
| Part number | 1.324-302.0 | 1.324-304.0 |
| Max pressure | 20 to 130 bar | Same pump |
| Flow | 420 L/h | Same |
| Area (Kärcher figure) | 30 m²/h | Same |
| Hose | 8 m PremiumFlex | Same |
| Motor | 1.8 kW, water-cooled | Same |
| Weight (bare, Kärcher) | 11.5 to 12.2 kg | Same machine, T 5 in the carton |
| Gun / lance | G 160 Q Power Control, Vario, dirt blaster | Same |
| Home extras | None | T 5 plus 1 L stone and façade cleaner |
| Typical UK price, Aug 2026 | Screwfix £199.97. B&Q £209. Official £219.99. Amazon around £200 (RRP £240) | PriceSpy from £209.99. Viking has listed £219.99 excluding VAT |
Prices checked August 2026. Home and Car & Home boxes cost more. Confirm the T 5 is in the carton before you add one separately.
Who it is for
This is the default household washer in the 130 bar class. Buy it if most of the list below is true.
- You have an outdoor tap and a 13A socket.
- The jobs are cars, bikes, garden furniture and a normal UK patio or short parking bay.
- You want one machine, not a cheap first washer you will replace next spring.
- You will use a twist-to-adjust Vario: low for paint and glass, open for arches and stone.
- Eight metres of Flex hose will reach around a family hatchback if you park the trolley at a corner.
- You do not already own a working K4. If you do, buy a head or a foam jet, not another pump.
That is most UK houses that are shopping a yellow washer in good faith. The Kärcher hub already treats this SKU as the home default.
Skip it if
- The drive is long and green. 30 to 40 m², north-facing, or a hose run that already has you dragging the trolley halfway down the path. That is a K5 conversation. Read K4 vs K5 and the driveway page. Do not stretch this K4 and hope.
- You only rinse one small car and will never touch the slabs. A K2 will do that for about half the money. See K2 vs K4 and the budget page.
- There is no outdoor socket, or no tap. A longer hose will not invent a 13A point. That is a cordless job, not a bigger K-class.
- You want a hose reel in the body. The Flex coils on a hook. A reel is a different machine on the electric hub, not a K4 option.
- You already own this pump. Add a T 5 or a foam jet. Another Flex is a duplicate.
Kärcher K4 Power Control Flex
The default Kärcher for a UK home
- Buy: Amazon around £200 (RRP £240) · Screwfix £199.97 · B&Q £209 · Kärcher UK £219.99
- Part number: 1.324-302.0
- Pressure / flow: 20 to 130 bar, 420 L/h
- Hose: 8 m PremiumFlex
- Motor: 1.8 kW, water-cooled
- Weight: 11.5 to 12.2 kg without accessories
- In the box: G 160 Q Power Control gun, Vario Power lance, dirt blaster, garden-hose adaptor
- Who it is for: cars, bikes, furniture and a normal patio, if you have a tap and a 13A socket
130 bar with a twist-to-adjust Vario is the useful home class. Drop the setting for paint and glass. Open it for arches and stone. The LED on the G 160 Q shows the step, so you are not guessing. Kärcher’s own area figure is 30 m²/h. Treat that as a catalogue number, not a promise that a filthy terrace will be done in an hour.
Buy this Flex SKU, not an older stiff-hose K4. Flex is the PremiumFlex hose. Power Control is the gun that shows the step. Classic in the same 130 bar class is a different carton: often cheaper, often a stiffer hose. Shop the part number on the box, not the word K4 on a tile.
Hose and daily use
Eight metres walks a family hatchback if you park at a corner. It will not let you stand still on a long van. You will move the trolley once on a short bay. You will drag it on a long path. That daily irritation is the honest reason people step to a K5, not the extra 15 bar on a bonnet.
The hose is the comfort you pay for over a K2. A K2 Home is 4 to 5 m. Classic and Horizontal are 3 m. Those lengths turn a car wash into a dance. The Flex coil lives on a hook, not on an internal reel. If a reel is the feature you came for, this is the wrong machine.
Gun, Vario and dirt blaster
The Vario is the car-safe tool. Wide fan, a metre back, for paint. Closer and more open for wheels and arches. The dirt blaster is for paving and stubborn stone, not lacquer. Leave it on the hook when the car is out. People leave it clicked on by mistake. That is how badges lift and clearcoat marks.
Plug ‘n’ Clean sits in the body if you want shampoo through the lance. Fine for a quick wash. It is not a snow-foam layer. A dedicated FJ 10 C foam jet is about £30 to £33 and is the better car accessory. How to layer foam, mitt and rinse sits on the cars page and the foam cannon guide.
Motor, weight and care
The 1.8 kW motor is water-cooled. That is the real step up from the air-cooled K2 class: quieter, happier in a long session, less of a toy. The trolley is about 12 kg without the extras. You will wheel it, not carry it up a flight of stairs every weekend. If stairs are the constraint, a lighter mains box on the electric hub is the honest alternative, not a smaller Kärcher with a 3 m hose.
Rinse the inlet filter. Drain the pump before frost. Register the machine if you want the extra Kärcher years on top of the standard two. Terms apply. First-use setup, the garden-hose adaptor, and winter drain-down are on how to use a pressure washer.
Kärcher K4 Power Control Flex Home
The K4 to buy if you also want the patio head
- Buy: Amazon Home (PriceSpy from £209.99) · Viking has listed Home at £219.99 excluding VAT · Kärcher UK Home
- Part number: 1.324-304.0
- In the box: the K4 Flex, T 5, 1 L stone and façade cleaner, Vario, dirt blaster, 8 m Flex hose
- Who it is for: households that need a washer and a patio head, and do not already own either
Home means a T 5 in the carton, not a different pump. Same 130 bar and 420 L/h as the bare Flex. The T 5 is the everyday 280 mm hood (2.644-084.0), K2 to K7. It is not the small T 1 that ships in a K2 Home box. Do not then add a second T 5. Retailers will happily sell you one.
A separate T 5 is from about £55. Screwfix has it at £58.99. If the bare Flex is £200 and the head is £55, a Home box at about £210 to £245 is a small premium. A Home box at £280 is a luxury. Shop the live total and the contents list.
A K4 will spin a T 5 properly on a typical terrace. It will not pretend to be a K5 on a 30 to 40 m² north-facing drive. If the patio is large, filthy and you already know you will be out there twice a year, read K4 vs K5 before you lock this kit. Full head notes sit on the Kärcher patio cleaner page.
Skip the Home box if you already own a working K4. Buy the T 5 on its own. Skip it if the only hard surface is a 3 × 4 m yard you will rarely wash. The bare Flex is enough, and you can add a head later.
Which carton
- One machine for cars and a normal patio, no head yet. Bare Flex if you might never use a T 5. Home if you know you will.
- Patio is why you are shopping. Flex Home. Confirm the T 5 is in the list. Do not buy a K2 Home and hope the T 1 will do a green terrace.
- You already own the washer. T 5 on its own, from about £55. Not another K4.
- Car extras look cheap in a bundle. Car & Home adds foam, a brush or shampoo on top of the patio kit. B&Q has listed that box at £259. Amazon Car & Home has been around £298. Useful if the extras are genuinely cheap in the live total. Easy to overpay when the banner just says Home. Pointer only: B&Q Car & Home.
Shop the part number. 1.324-302.0 is the bare Flex. 1.324-304.0 is Flex Home. Older stiff-hose K4 boxes still appear in search. Flex is the one to take home.
T 5 as an add-on
A T 5 is a clip-on head, not a washer. Without this K4 (or another K-series mains machine), a tap and a socket, it does nothing. Buy it separately only if you already have the pump, or if a Home box is more expensive than Flex plus head.
- T 5 (2.644-084.0): 280 mm hood, K2 to K7. From about £55. Screwfix £58.99 · Trafalgar · Wickes · Kärcher UK
The T 7 Plus is a corner-jet head, K4 to K7 only, from about £75. Worth a look if you already own this machine and hate the edges a T 5 leaves. Not a reason to buy a second washer. Neither head clips onto a Bosch or Nilfisk.
Cars and foam
A car does not need more than this K4. It needs a wide fan, distance, and enough hose to walk the body without yanking the trolley. Kärcher’s own advice is a flat jet, at least 15 cm from paint and 30 cm from tyres. Further is safer. Stay on the Vario. Keep the dirt blaster off the lacquer.
Foam is worth more than another 15 bar on paint. Do not buy a Car & Home carton just to get a bottle you can clip on afterwards. Do not buy a K5 because a listing mentioned snow foam. The wash order is on the cars page. The accessory path is the foam cannon guide.
FAQ
Is the Kärcher K4 good enough for a UK home?
Yes, if the home is the usual one: a tap, a socket, one or two cars, furniture, a short bay or a normal patio. That is what the 130 bar Power Control Flex is for. It is the default household buy in this class, not a compromise while you save for a K5.
Should I buy the Flex or the Home kit?
Bare Flex if you might never use a patio head. Home if you do not already own a T 5 and you will use one. Bare Flex plus a separate head is often close to a Home box at about £210 to £245. A Home box at £280 is a luxury. Shop the live total.
Can I wash a car with a K4?
Yes. Wide Vario, distance, dirt blaster off the paint. Foam first if you have a jet. This is the machine the cars page is written around. The extra bar on a K5 is for the drive, not for getting closer to the wing.
Is the K4 a K5, or is it just a dear K2?
Neither. A K2 is 110 bar, air-cooled, 3 to 5 m of hose. Fine for one small car. Not a driveway machine. A K5 is the same gun family with more water and a 10 m hose, for a long or filthy drive. This K4 sits in the middle on purpose. Class arguments stay on K2 vs K4 and K4 vs K5.
Is 8 m of hose enough?
For a hatchback on a short drive, yes, if you park the trolley at a corner. For a long van, a 30 to 40 m² plot, or a tap at the wrong end of the path, no. That daily reach problem is how you know you wanted a K5.
Do I need to register it?
The standard warranty is two years. Register the machine if you want the extra Kärcher years. Terms apply. The water-cooled motor lasts longer than an air-cooled K2 if you rinse the filter and drain the pump before frost.
More reading
The yellow range in full is the Kärcher hub. Brand-agnostic mains picks sit on the electric guide. Cars, driveway, foam and first use are linked above. If you will not spend £200, start on the budget page.