What Is Cavitation And How Can It Affect A Pressure Washer?




What Is Cavitation And How Can It Affect A Pressure Washer

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PressureWasherWisdom.com is your go-to resource for all things pressure washing. Whether you’re just starting your cleaning journey or you’re a seasoned pro, their range of services, product reviews, gift guides, and expert advice will help you make informed decisions and enhance your pressure washing techniques. In this article, we’ll be diving into the topic of cavitation and exploring its impact on pressure washers. So, let’s get ready to uncover the secrets of cavitation and how it can affect your pressure washing experience.

What Is Cavitation

Cavitation is a phenomenon that can occur in pressure washers, affecting their performance and durability. It is important to understand what cavitation is, its causes, and its effects in order to prevent and address this issue effectively.


Cavitation refers to the formation of tiny air bubbles in the water flowing through a pressure washer’s pump. These bubbles are formed when the pressure within the pump drops to a point where the water boils, creating vapor pockets. As the pressure increases again, these vapor pockets collapse, causing shock waves that can be damaging to the pump and its components.


Several factors can contribute to the occurrence of cavitation in a pressure washer:

  1. Improper Water Supply: Insufficient or low-quality water supply can lead to cavitation. If the water source does not provide enough volume or pressure, the pump may not receive an adequate flow of water, causing it to draw in air and form bubbles.
  2. High Pressure: Ironically, operating a pressure washer at excessively high pressures can also lead to cavitation. When the pressure is too high, it can cause a sudden drop in pressure within the pump, resulting in the formation of vapor pockets.
  3. Blocked or Damaged Nozzle: A nozzle that is blocked or damaged can disrupt the smooth flow of water, causing turbulence and pressure fluctuations within the pump. This turbulence can lead to the formation of air bubbles and subsequent cavitation.
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The occurrence of cavitation can have detrimental effects on both the cleaning efficiency and overall lifespan of a pressure washer:

  1. Decreased Cleaning Efficiency: When cavitation occurs, it affects the pressure and flow of water coming out of the nozzle. This can result in reduced cleaning power, making it more difficult to remove dirt, grime, and other substances from surfaces.
  2. Damage to Pump and Components: The collapse of vapor pockets during cavitation can create intense shock waves that can cause damage to the pump, valves, seals, and other internal components. Over time, this can lead to costly repairs or the need for replacement parts.
  3. Increased Maintenance Needs: Cavitation puts additional stress on the pressure washer’s pump, reducing its overall lifespan and requiring more frequent maintenance. This increased maintenance can include more frequent cleaning, inspections, and the replacement of damaged parts.

How Cavitation Affects Pressure Washer Performance

Understanding how cavitation affects the performance of a pressure washer is crucial for recognizing and addressing this issue:

Loss of Cleaning Power

Cavitation directly impacts the pressure and flow of water coming from the pressure washer. With the formation of air bubbles, the force behind the water is compromised, leading to decreased cleaning power. Surfaces may not be cleaned as thoroughly as desired, requiring additional time and effort to achieve satisfactory results.

Inconsistent Pressure Output

As cavitation occurs intermittently, the pressure output of the pressure washer can become inconsistent. This can make it challenging to maintain a steady stream of water, resulting in uneven cleaning patterns and potential streaking on surfaces.

Reduced Lifespan of Equipment

The repeated occurrence of cavitation subjects the pressure washer’s pump and components to undue stress. Over time, this can lead to premature wear and tear, reducing the overall lifespan of the equipment. Regular cavitation can result in the need for costly repairs or even the replacement of the pressure washer.

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Signs of Cavitation

Recognizing the signs of cavitation is essential for quickly addressing the issue and preventing further damage to the pressure washer:

Unusual Noise

One of the most noticeable signs of cavitation is a distinct change in the sound produced by the pressure washer. You may hear a rattling or knocking noise, indicating the occurrence of air bubbles collapsing within the pump. If you notice any unusual or inconsistent sounds while operating the pressure washer, it is important to investigate for possible cavitation.

Fluctuating Pressure

Cavitation can cause pressure fluctuations as the vapor pockets collapse and the water flow is disrupted. If you notice that the pressure output from the pressure washer is inconsistent or varies significantly, it may be a sign that cavitation is occurring. Monitoring and addressing these pressure fluctuations is crucial to prevent unnecessary damage to the equipment.

Internal Pump Damage

Regular cavitation can lead to internal pump damage, which may eventually result in visible signs such as leaks or reduced performance. Inspecting the pump regularly and checking for any signs of deterioration or damage is essential for preventing further issues and ensuring the longevity of your pressure washer.

Preventing Cavitation

Fortunately, there are several measures that can be taken to prevent cavitation and maintain the optimal performance of your pressure washer:

Proper Water Supply

Ensuring an adequate and consistent water supply is crucial in preventing cavitation. Consider the following factors:

  1. Using an Adequate Water Source: Ensure that the pressure washer is connected to a water source that can deliver the required flow rate and pressure. If your current water supply is insufficient, you may need to consider alternative sources or install a booster pump.
  2. Avoiding Long Hose Lengths: Excessive hose lengths can increase friction and decrease water flow, potentially leading to cavitation. Keep hose lengths as short as possible while still allowing for convenient operation.
  3. Keeping Inlet Filter Clean: Regularly clean and maintain the inlet filter of your pressure washer. A clogged or dirty filter restricts water flow and can contribute to cavitation.
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Use of Pressure Washer Accessories

Certain pressure washer accessories can help prevent cavitation and improve overall performance:

  1. Nozzle Filters: Using nozzle filters helps prevent clogs and blockages, ensuring a smooth and consistent flow of water through the nozzle. This reduces the risk of turbulence and cavitation.
  2. Surface Cleaners: Utilizing surface cleaners can distribute water evenly over a larger area, reducing the strain on the pump and minimizing the likelihood of cavitation.
  3. Foamers: Foamers allow for the application of detergents in a frothy foam form. The thick foam reduces the risk of cavitation by evenly distributing the detergent and preventing excessive pressure drops within the pump.

Regular Maintenance

Regular maintenance is essential for preventing cavitation and ensuring the longevity of your pressure washer:

  1. Cleaning and Inspecting Nozzles: Regularly remove and clean the nozzles, checking for any debris or obstructions that may disrupt the flow of water. Inspect the nozzles for any signs of wear or damage, replacing them as necessary.
  2. Replacing Damaged Parts: Any damaged or worn-out parts should be promptly replaced to prevent further issues and ensure optimal performance. This includes seals, valves, and other components that may be prone to damage from cavitation.
  3. Using Proper Detergents: Selecting and using detergents specifically formulated for pressure washers can help prevent the buildup of dirt and debris within the pump. Regularly flush the system with clean water to remove any residue from the detergents.


Cavitation is a common issue that can affect the performance and lifespan of a pressure washer. Understanding the causes and effects of cavitation, as well as the signs to look out for, is essential for maintaining the efficiency and durability of your equipment. By following preventative measures such as ensuring the proper water supply, utilizing pressure washer accessories, and performing regular maintenance, you can significantly reduce the risk of cavitation and keep your pressure washer running smoothly for years to come.

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