Why does the pressure washer stutter?

While pulsing in a pressure washer tends to indicate problems in the direction of water pressure, stuttering signals an undersupply of water. This can be due to the supply, the accessories used or a cause within the unit. In many cases it is due to a supply fault, less often to a technical cause.

Stuttering arises from lack

As long as water flows into the high-pressure cleaner in an ideal quantity, is provided with exactly the required volume in the inlet pipe, filter and piston chambers, flows on compressed in a suitable cross-section and is not obstructed by the dispensing gun and nozzle opening, stuttering is impossible.

Stuttering, as distinct from the pulsation of the pressure washer, is rarely a consequence of air in the system. However, there are mixed forms which increasingly indicate a disturbance of the pressure situation, which can also be due to the so-called cavitation.

More on the topic: Pressure Washer Repair

Physical characteristic of cavitation in hot water devices

Cavitation causes the bubbles that form when water boils. At normal atmospheric air pressure, the evaporation point is 100 degrees Celsius. This point increases with water pressure. If the speed of the pressure build-up does not “keep up” with the hot and flowing water, steam bubbles can temporarily form. When the pressure “catches up” with the evaporation point again, the bubbles implode by condensation and water takes their place again. This can lead to a stuttering water flow.

Practical causes that can trigger stuttering

With incoming water

  • Water tap fully turned on
  • Water pressure in the supply pipe sufficient

Space available for the water

  • Cross-section of pipes
  • Dirty and clogged nozzle opening
  • Dirty or defective valves

For outgoing water

  • Gun leaking
  • Pressure pipe has too small a cross-section
  • Lance has too small a cross-section
  • Nozzle cross-section or outlet opening is too small

Also of interest: How to Properly Maintain Your Pressure Washer

Compatibility of the individual parts

The components that are matched to each other also have an influence on the “healthy” flow of water. If all water-carrying appliance parts are from the same manufacturer and designed for the same model, the risk of a lack of space and flow behaviour is minimised. This also applies to supplementary accessories such as foam lances, dirt cutters and other attachments. The material of the inner walls alone can cause stuttering.

You can roughly check the tap water pressure with a ten-litre bucket. Fill it with the water that is fed into the high-pressure cleaner ( connection hose on the tap). It should be full after one minute.

Alfred Harper

Alfred Harper

Alfred Harper is a former consultant and product expert at a company producing cleaning equipment. He was working at this position for more than 10 years and has gained incredible experience and knowledge as he has tested almost all pressure washers brands and models and became an expert in this field. Now, he is writing reviews and how-to articles about pressure washers and makes a great contribution to the Pressure Washers company to help people to choose the best cleaning equipment for home use.

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