Consumables
Choosing a nozzle
You cannot change the pump. You can change the nozzle, and that changes the force at the surface far more than any machine upgrade.
The nozzle is where pressure becomes force, and it is the only part of the system you can change in ten seconds.
Fan angle
A wide fan spreads the same energy over more surface: gentler, slower, safer. A narrow fan concentrates it: faster, and capable of damage. Most domestic machines fit a variable lance that covers the useful range, and that lance is what you should reach for by default.
The rotary nozzle
Hard mineral surfaces only. It is a stripping tool, not a cleaning tool, and the damage it does to decking and render happens in one pass.
Size matters, and it is not marked helpfully
Nozzle bores are matched to a machine’s flow. Fit one from a larger machine and pressure falls; fit one too small and the unloader cycles. When buying a replacement, buy by machine model, not by looks.
When to replace one
When pressure drops gradually over months, or when the fan develops a gap or a wandering edge. Nozzles wear from the inside and nothing about that is visible. It is the cheapest fix on the machine and the first one to try.
Questions people actually ask
What is a rotary nozzle actually doing?
It spins a single pencil jet in a cone, so you get the concentrated force of a zero-degree jet spread over a circle instead of a line. On concrete it roughly halves the time. On timber, render or a car it removes material, and no distance is fully safe.
Why do the same bar figures feel different on two machines?
Because force at the surface depends on flow through the nozzle, not on the pressure at the pump. A worn nozzle passes more water at lower pressure and feels weak; a nozzle sized for a bigger machine will drop your pressure outright.