Every serious complaint we hear about a pressure washer falls into one of two groups. It has lost its power, or it has wrecked something expensive.
A surprising share of both traces back to a brass tip worth a few pounds.
The nozzle is the last thing anyone thinks about. It is also the only component that touches every job you do.
It sets your working pressure, and it decides what the water does when it lands. Then it wears out quietly while you blame the pump.
The nozzle sets the pressure, not the pump
This is the part that catches people out, so it is worth being blunt about it.
Your pump produces flow. It pushes a fixed volume of water every minute, and it does not care what happens afterwards. Restricting that flow creates pressure, and the restriction is the nozzle orifice.
Squeeze the same flow through a smaller hole and pressure climbs. Open the hole up and pressure falls, and the pump does the same work either way.
Two things follow from that, and they matter.
A worn nozzle lowers your pressure. Not slightly. As the orifice erodes, it passes more water at less pressure.
The machine feels tired, but nothing inside it has failed, and you blame a pump that is doing its job.
An undersized nozzle overloads the machine. Fit a tip meant for a smaller machine, and you drive pressure past the unloader setting. The safety valve works harder, the pump works harder, and nothing lasts as long.
Why the number on the nozzle has to match the machine
Kränzle nozzles carry a size code. You will see 028 or 042 stamped on lances and listed on parts.
That number is not a style choice: it matches the flow of a particular machine.
As a rough guide, the smaller number suits the smaller machines. A stub lance marked 028 pairs with a 7/122 or a TS. A 042 lance pairs with the 10/122, K 1154 TST and K 2160 class of machine.
Check your model before you order a tip. Mixing them up is one of the most common causes of a tired machine.
You hear it as "never felt right after I bought new bits for it". If you are unsure, tell us the model number, and we will tell you the size.
The fan angles, and what each is actually for
Spray angle changes how the same energy spreads across the surface. Narrow means concentrated and aggressive, while wide means gentle and fast.
- 0 degrees. A pencil jet. It will cut. There is almost no legitimate cleaning use for it. It is the fastest way to carve a line into concrete or take a lump out of render. Leave it in the box.
- 15 degrees. Aggressive, and it shows. Stubborn deposits on hard, sound surfaces only. Steel, concrete, heavy plant.
- 25 degrees. The workhorse for most outdoor cleaning. Enough concentration to do real work, wide enough to cover ground.
- 40 degrees. Rinsing, vehicles, painted surfaces, anything delicate. Also the fastest nozzle you own for a final rinse, because coverage beats concentration once the dirt has lifted.
- Low pressure or chemical. A wide, soft pattern that opens the chemical injection route. Applying detergent at high pressure is wasted product and wasted time.
Most jobs need two of these and one lance change. If you are doing everything on one nozzle, you are either being slow or being rough.
The turbo nozzle problem
A Dirtkiller or turbo lance spins a zero-degree jet in a cone. You get the cutting power of a pencil jet across the coverage of a 25-degree fan. That is why it clears years of green off concrete in a fraction of the time.
It is also the single most destructive accessory you can buy.
Good on: concrete, hard engineering brick, stone flags in sound condition, steel, heavy plant, cast iron.
Bad on: soft sandstone and limestone, old mortar joints, render, timber decking, painted surfaces, vehicle bodywork, anything pointed, anything Victorian.
The failure mode is not dramatic: it is a faint spiral pattern you only notice once the surface dries.
By then it is in the material for good. We have written separately about surface damage, because it is the mistake that costs customers real money.
Test in a corner. Every time. On every new surface. Thirty seconds of caution against a resurfacing bill is not a difficult trade.
The worn nozzle you are not noticing
Nozzles erode. Water carrying grit passes through a small brass hole at very high speed. Over a few hundred hours, that hole gets bigger and loses its shape.
How to spot it:
- The pressure gauge reads lower than it used to at the same settings
- The spray pattern looks ragged or lopsided rather than a clean, even fan
- Jobs take longer, and you find yourself working closer to the surface to compensate
- A new nozzle feels like a different machine
A worn tip can cost you a real slice of your working pressure. The pump, the hose and the gun can all be in perfect order. It is the cheapest thing on the machine and usually the first thing to fail.
Keep a spare set, and replace them on condition rather than waiting for a complaint.
Never poke a blocked nozzle with wire, because that ruins the orifice for good. Soak it, or back flush it, or bin it.
Distance is a control, not an accident
The nozzle is half the story, and the other half is where you stand.
Impact energy drops away with distance. Move from 100mm to 200mm, and you do not lose a little; you lose most of it. That is a control you can use on every pass, with no lance change at all.
The working method that avoids damage: start well back. Move in slowly until the dirt starts to lift, then stop.
Keep the lance moving, keep the angle consistent, and overlap your passes. A steady sweep from a sensible distance beats a hovering blast every time, and it leaves no tiger stripes.
Frequently asked questions
What do pressure washer nozzle numbers mean?
The number refers to the orifice size, matched to the flow rate of a particular machine. Kränzle sizes such as 028 and 042 pair with specific models.
A lance sized for a 7/122 is not correct for a 10/122. Fitting the wrong size either drops your pressure or overloads the pump, so check your model number before ordering.
Which pressure washer nozzle should I use for a patio?
A 25-degree fan for general cleaning, or a surface cleaner if you want an even finish without stripes. Only reach for a turbo nozzle on hard, sound concrete. Never use one on soft sandstone, old mortar, or anything already crumbling.
Why has my pressure washer lost pressure?
Check the nozzle before anything else. An eroded orifice passes more water at lower pressure, and it drops your working pressure without any other symptom.
Also check the water supply and the inlet filter, since starving the pump produces similar complaints.
Can a turbo nozzle damage a patio?
Easily. It concentrates a zero-degree jet into a spinning cone. That cone etches spiral marks into sandstone, limestone, render and old mortar joints.
Always test on a hidden corner and let it dry before committing to the whole area.
How often should pressure washer nozzles be replaced?
On condition rather than on a schedule. Replace when the spray pattern goes ragged, or when gauge pressure drops with everything else in order.
A fresh nozzle that outperforms the old one tells you the same thing. Machines working in gritty water wear them out much faster.
The bottom line
The nozzle is the cheapest part on the machine. It controls your pressure, your speed and your risk of doing damage.
Match the size to your model and carry a 25 and a 40. Treat the turbo lance as a specialist tool rather than a default. Replace tips before they start costing you time.
Kränzle UK stocks the full range of lances, nozzles and quick release fittings. We will match them to your exact model if you tell us what you are running.