That is a good question with a not-so-easy answer.

‘You should replace it when it is worn’ is the easy answer. But how long do they last?

Most operators have an attitude of ‘If it ain’t broken, why fix it?’, but what they don’t realize is that if a nozzle on a pressure washer wears away (and they do) by a small margin, you will experience an amplified drop in pressure and cleaning capacity, which means:

• Longer cleaning (waste of time, increase in cost)
• Less efficient cleaning

If a pressure washer’s nozzle’s diameter increases by as little as 10% due to wear, you will experience a 21% drop in pressure.

But how often do you need to replace a high pressure nozzle?

That depends on:

• The water quality (mostly dissolved minerals which will wear the nozzle faster)
• Your operating pressure
• The amount of use

These three factors will wear away a nozzle at different rates. The easiest way to know if a nozzle is worn, is look at the operating pressure on the pressure gauge and recalling what it was when the unit was new. If there has been a 10% or more drop in pressure, it is time for a new nozzle. And when a nozzle change doesn’t make a difference, then it may be time to refurbish or replace the by-pass (unloader) valve and only then would you bother changing seals on the pressure pump.

So, when your pressure washer’s pressure drops, replace the nozzle. It is a consumable item and should be changed regularly for top performance and effective cleaning!