Pressure washers, nozzles, hoses and pump storage

Petrol and electric pressure washers: nozzles, inlet screens, hoses, couplings and seasonal storage. Every procedure here starts the same way — the machine switched off, the water supply shut, the power source removed and the trigger squeezed until the stored pressure is gone. That release step is the reason the rest of the page is safe to do.

Common failure modes

• A partly blocked nozzle, which reads to the owner as a failing pump
• An inlet screen packed with grit, which starves the pump and destroys it quietly
• Air left in the system after a hose change, which makes the output pulse
• The machine run with no water supply open, which wrecks the seals in seconds
• Water left in the pump over winter, which freezes and splits the housing
• A hose kept in service after its outer cover has been cut or blistered

Procedures

• Inspect a pressure washer hose, couplings and O-rings before useA leak at a pressure washer coupling is usually a five-cent O-ring, not the hose. This page walks through both: examinin
• Check that a water supply can feed a pressure washer before the machine is startedPrevent pump damage by testing water supply adequacy before starting a pressure washer. Measure inlet water pressure and
• How to choose the right pressure washer nozzle for the surface you are cleaning, and what the colours actually meanPicking a tip is the decision that does the damage. The narrow nozzle looks like the powerful one, people reach for it f
• How to check and change pressure washer pump oil, and how to tell if your pump even has oilA pressure washer has two engines' worth of oil to think about, and most owners know only one of them. The engine has it
• Clear a blocked pressure washer nozzle and inlet screenPressure that drops off, a spray that surges, or a pattern that sprays sideways usually comes from one of two cheap part
• How to use the soap or detergent injector on a pressure washer, and why nothing comes out of itA pressure washer that will not spray soap has not necessarily failed. On most machines the detergent only draws through
• How to winterize a pressure washer pump before freezing weather, and what to put in itA pressure washer that goes into the shed in October with water still in it can be scrap by March. Water left in the pum

Where this stops

The pump, the unloader valve and any component that holds pressure are not homeowner work and are not covered here. Nozzle and screen cleaning is covered, and only after the machine is off, the supply is shut and the stored pressure has been released. A pressure washer jet can drive water, detergent and grit through unbroken skin: the wound left behind looks like a pinprick and the damage under it is not, so a jet is never aimed at a person or an animal, and a suspected injection injury needs immediate medical assessment however small the mark looks. Working at height with a pressure washer, and any use of a jet on a roof, is deferred.