How to Use a Pressure Washer (UK, 2026)

How to use a pressure washer is mostly setup, the nozzle and how far you stand back. A 110 to 145 bar mains electric machine will wash a car, a patio, bins and garden furniture if you treat each surface as a different job. The same jet that lifts moss from concrete will cut into paint, raise timber grain and blow sand out of block paving.

This is the first-use guide for a UK home with a tap and a 13A socket. It is not a product roundup. For the machine itself, start with the cars guide if you have a tap, or the cordless guide if you do not.

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Before you start

Check three things that have nothing to do with the lance: water rules, where the dirty water goes, and who you will annoy.

Hosepipe bans. A Temporary Use Ban usually treats a mains-fed washer as a hosepipe. In summer 2026 several water companies have banned washing a private car, patio or path with a hose or a jet wash. A bucket is normally still allowed. A water-butt feed is not a free pass if the notice names pressure washers. Check your supplier first.

Runoff. Some councils restrict washing on the public highway even with no soap. On a private drive, keep dirty water out of a surface-water gully, a soakaway, a stream or a neighbour’s garden. Those gullies often run straight to a watercourse. Detergent, oil and silt are the problem. Aim rinse water at a foul or combined drain, or into soil on your own plot. If you cannot control the flow, skip the soap.

Neighbours and weather. A domestic electric washer is loud enough to fill a terrace. Do the long patio on a Saturday morning, not a Sunday evening, and keep the jet off their car, fence and open window. Electrical Safety First says not to use a washer in rain or a strong wind. Do not wash in a hard frost. Do not wash a car in midday sun: shampoo dries into spots.

You. Glasses if the job will splash. Closed shoes. Trigger lock on whenever you put the gun down. Never from a ladder. Never at a person, a pet or yourself.

How to set up a pressure washer

Do this in order. Water first, power second. Most first-use faults are a dry pump or a kinked inlet hose.

1. Read the sheet in the box. Inlet pressure, hose bore and whether the machine will siphon from a butt are model-specific. The steps below are the domestic electric pattern, not a substitute for that page.
2. Park on dry, level ground, close enough that the high-pressure hose reaches the far corner, far enough that you will not soak the trolley or the plug.
3. Rinse the inlet filter. Most Kärcher, Bosch and Nilfisk machines have a small mesh in the tap connector or the inlet. Grit in the pump is how a new washer dies in a season.
4. Fit a proper garden hose. Half-inch (12 to 13 mm) bore, unkinked, fully off the reel. A thin coiled hose starves the pump. Some manuals want several metres of uncoiled hose between tap and machine.
5. Turn the tap on fully. Open the trigger and let water run until the stream is steady. That purges air. Do it before you switch the machine on.
6. Then plug in. Use a splashproof outdoor socket on a 30 mA RCD, or an RCD adaptor if the circuit is not already protected. A weatherproof box is not the same thing as an RCD.
7. Skip the indoor extension. If you must add a lead, use one rated for outdoor use, fully unwound, coupling off the wet ground and out of the spray. Do not daisy-chain indoor reels.
8. Fit the lance and a wide fan or Vario tip. Lock the trigger while you click things on. Start on the lowest or widest setting, not the dirt blaster.
9. Switch on, then pull the trigger. Many pumps idle until the gun opens. If nothing comes out, switch off, unplug, and go back to step 5. Do not keep running a dry pump.
10. When you stop, lock the trigger, switch off, unplug, turn the tap off, then squeeze the trigger again to drop the residual pressure. That last squeeze stops the hose bursting in your hand when you undo the coupling.

If the motor starts then dies, or the RCD trips, stop. A wet plug, a nicked lead or a dead pump is not something you reset and ignore.

Nozzles and distance

The nozzle does more work than the bar figure on the box. A 130 bar machine on a 40° fan, a metre back, is gentle. The same machine on a 0° pencil jet, 5 cm from the surface, is a cutter.

Fan or Vario. The everyday tip. A wide fan (often 25° or 40°, or the low end of a Kärcher Vario) is for cars, furniture, glass from a distance, and a first pass on stone. Go narrower only when the dirt is still there and the surface can take it.

Soap / black tip. Low pressure. It applies detergent. It does not wash. Swap back to the fan to rinse.

Dirt blaster, rotary, turbo. A spinning pencil jet. Fine on concrete and dirty block. Wrong on paint, glass, plastic, tyres, timber, composite decking, soft stone and pointing. Leave it on the hook until the job is stone you are willing to mark.

Pencil / 0°. A solid needle. For a clogged grate or a lump of cement on a path, at a distance, if you accept the scar. Never on a car.

Distance. Kärcher’s own high-pressure working distance is about 30 cm. Closer is only for masonry you have already tested. On a car they want a flat jet, at least 15 cm from the paint and 30 cm from the tyres. Further is safer on old lacquer, wraps, chrome and anything with a camera in it. Keep the lance moving. A parked jet etches a stripe.

Test a hidden corner first. If the surface furs, pits or the colour lifts, you are too close or on the wrong tip.

Job	Tip	Starting distance	Notes
Car paint and glass	Wide fan / Vario low	30 cm or more (15 cm minimum)	No rotary, no pencil
Tyres and arches	Wide fan	30 cm or more	Foam and a brush beat more bar
Patio, concrete, dirty block	Fan, then rotary if needed	30 cm, then closer on a test patch	Patio head if you have one
York stone, sandstone	Wide fan only	40 to 50 cm	Easy to bruise
Timber or composite decking	Wide fan, low setting	30 cm or more	With the grain, keep moving
Bins and plastic furniture	Fan	30 cm	Watch stickers and wheels
Oil on a drive	Soap tip, then fan	30 cm	Detergent first, not more pressure

Surface by surface

Cars

A car is the surface people ruin first. Use a wide fan, stay back, and do not chase a tar spot with the dirt blaster. Pre-rinse to float grit, foam or shampoo, mitt if the film is heavy, then rinse on the same wide fan. Wheels and arches can take a step more pressure than the bonnet. Still not a pencil jet.

The full wash method, including what not to hit on a modern car, lives on the best pressure washer for cars page. Seals, cameras, parking sensors, soft-tops and lock barrels are how a ten-minute wash becomes a bill. Petrol machines and anything much over 150 bar working pressure are the wrong tool for gloss paint.

Patio and drive

Sweep first. Leaves, grit and a loose screw become projectiles. If you have a hooded Kärcher patio cleaner that clips on the lance, use it for the open area. It keeps the jet on the slab and cuts the stripe marks. Edges, steps and the lip against the house still need the lance.

Work in overlapping passes, walking backwards so you are not standing in the bit you just cleaned. On concrete and dirty block you can step from a fan to a dirt blaster once a test patch looks honest, not chewed. On York stone, sandstone and any slab that already sands off on your shoe, stay on the fan and stay back. You are cleaning film, not carving the face.

Block paving. The jointing sand is part of the surface. A rotary jet held in the joint will empty it. Sweep, wash the faces on a fan, and brush sand back in when the plot is dry. Weeds in the joints want a Ryobi patio cleaner, not a dirt blaster.

Oil. Degreaser or patio detergent on the stain, dwell time, then the fan. More bar on cold oil just pushes it into the next slab.

Against the house. Keep the jet off air bricks, weepholes, the damp-proof course and the bottom of rendered walls. Forcing water into the cavity is a much dearer job than a green patio.

Decking

Treat timber and composite as two different materials.

Timber. Wide fan, with the grain, keep moving, further back than you think. A close rotary jet raises the grain and leaves a fuzzy deck that then holds more algae. Soap and a deck brush do more for green film than another 20 bar. If the boards are already rotten, a washer will find the soft spots. That is not a reason to use one.

Composite. Check the board maker. Many UK ranges allow a low-pressure fan rinse and forbid a pencil jet. If the booklet is missing: wide fan, 30 cm or more, with the grain, no rotary, no bleach. Do not fire into the gaps. Water forced under the boards sits on the joists. If the surface furs, stop and finish with a hose and a soft brush.

Bins

Open the lid, pull the bin onto a drain or soil you own, and wash the inside on a fan. A squirt of detergent, a minute to dwell, then rinse. Do not stand in the splash. Do not blast the hinges, the wheels or the council chip. Wash the outside last. In a hosepipe ban this job often sits on the banned list.

Garden furniture

Plastic chairs and a resin table are fine on a fan at 30 cm. Teak and hardwood want the decking rules. Cushions come off. A barbecue gets the lid and trolley, not the burners or gas fittings. Bikes: fan on the frame, keep the jet out of hubs and any e-bike electrics.

Soap

Soap is a low-pressure job. Fit the soap tip or twist the Vario to the detergent setting, apply, wait, then rinse on the fan. High-pressure soap just wastes shampoo and sends foam into the drain.

Match the detergent to the surface. Car shampoo or snow foam on paint. Stone or patio cleaner on slabs. A deck cleaner on timber if the maker allows it. Washing-up liquid on a car strips wax and dries seals. Patio detergent on a bonnet dulls lacquer. Bleach on composite or coloured stone is a common way to void a warranty and bleach the lawn.

Do not build a pile of foam that slides off under its own weight. Do not let it dry. Work a panel or a bay at a time. Rinse the bottle and the lance after, or the next rinse still spits soap.

Soap is also the bit councils and the Environment Agency care about. If the only path for the water is a road gully, skip the detergent, or take the car to a wash that already treats the water.

What not to blast

If the surface is soft, hollow, electrical or older than it looks, put the gun down.

• People, pets, bare skin. The jet injects water and dirt. That is a hospital trip.
• Live electrics. Outdoor sockets, lights, an EV charger, a heat pump, a spur on the wall. Cover them. Never aim at them.
• Windows at close range. A fan from well back will rinse glass. A rotary jet will craze a unit or drive water into the frame.
• Soft render, pebble dash, crumbling mortar.
• Air bricks, weepholes, the DPC. You are watering the cavity.
• Asbestos cement. Old garage roofs, some soffits, some sheds. If you think it might be asbestos, stop.
• Rotten fences and flaking paint. The washer removes the last of the board, not the dirt.
• Engine bays, fuse boxes, aftermarket ECUs.
• Soft-top fabric and plastic rear windows.
• Children’s toys with stickers, seams or batteries.
• A ladder, a roof, or anything that needs both hands for balance.

If you are not sure what the surface is, it is not a washer job.

Frost, drain-down and storage

A UK frost will crack a pump that still has water in it. A lot of domestic warranties exclude that, including typical Kärcher terms. Empty the machine every time the forecast drops to zero, not only at the end of October.

After the last job of the day:

1. Turn the machine off and unplug it.
2. Shut the tap. Disconnect the garden hose.
3. Squeeze the trigger to dump pressure.
4. Disconnect the high-pressure hose and hang it so it empties.
5. With the inlet open and the high-pressure hose off, switch the machine on for a few seconds only, until the pump stops spitting water, then switch off. That is the brief dry run the manuals describe, not a minute of a screaming motor.
6. Empty any detergent bottle. Tip water out of the patio head and the gun.
7. Store the body, gun, hose and lances in a frost-free room. An unheated shed is not frost-free in January, even with a cover on the machine.

Rinse the inlet filter. Coil the hose loose. Do not park the trolley next to a boiler: cooked seals leak in April. If the machine must sit in a cold garage, a pump-guard or frost-care kit is the extra step. It is not a reason to skip the drain-down.

When cordless or petrol is the better tool

A mains electric washer is the default for a UK house with a tap and a socket. Change tool when that sentence is false.

No outdoor tap, or no socket. A battery gun that siphons from a bucket, or a small trolley with a tank, is the workaround. It will rinse a car and do furniture. It will not strip a mossy patio the way a K4 does. See the best cordless pressure washer UK guide.

A long drive, a yard, or the job is 40 metres from the house. A petrol machine brings more flow and no 13A lead. It also brings noise, weight, fumes and a jet that is too easy to mark paint with. Use it on stone and plant, not on a family car. See the best petrol pressure washer guide.

You only wanted to wash one small car, once. A bucket, a mitt and a visit to a car wash still win. Buying a washer for a single job is how machines sit wet in a shed and freeze.

FAQ

How far should I hold the lance?

Start at about 30 cm on a wide fan and only move in after a test patch. On a car, Kärcher wants at least 15 cm from paint and 30 cm from tyres. On timber, composite and soft stone, stay at 30 cm or more and keep the lance moving.

Can I use a pressure washer on a car?

Yes, on a wide fan, at a distance, with car shampoo rather than patio cleaner. No dirt blaster, no pencil jet, no close work on seals, cameras or a soft-top. The step-by-step is on the cars page.

Do I need detergent?

For road film, green growth and bin slime, yes. Apply on the low-pressure soap setting, do not let it dry, rinse on the fan. Skip soap if the only runoff path is a road gully.

Is it legal to wash my car on the drive?

Usually, on private land, if the dirty water does not go into a surface-water drain, a soakaway or a watercourse, and if no hosepipe ban is in force. Some councils restrict washing on the public highway even with no soap. Check the council and the water company.

Can I use an extension lead?

Only an outdoor-rated lead, fully unwound, on an RCD-protected supply, with the coupling kept dry. Do not daisy-chain indoor reels.

What happens if I leave water in the machine over a frost?

The pump can crack. Drain the hoses, dump the residual water with a brief run, and store the body indoors. Frost damage is often outside the warranty.

When should I not use a pressure washer?

In a hosepipe ban that names hoses or jet washes. In rain, a strong wind or a hard frost. On asbestos, soft render, air bricks, live electrics, a rotten fence, a soft-top, or any surface you have not tested. A mossy half-acre with no socket is a petrol conversation, not a bigger nozzle on a K2.