Why is My Power Washer Pulsating? - Pressure Washer
Skip Navigation

Pressure Washer relies on readers. We may earn commissions when you purchase through our links. Check Affiliate Disclosure

Why is My Power Washer Pulsating?

Why is My Power Washer Pulsating?

The power washer works well when you do its maintenance regularly. However, sometimes you may feel that your power washer is pulsating. Pulsating of the power washers is also accompanied by irregular water flow. You can fix the pulsating easily if there is a minor problem. But if the problem is big, then you may have to replace your power washer. Pulsating can be due to different reasons, such as blockages and leaks in parts, Trigger problems, clogged nozzles, and many more. Let’s have a look at why is your power washer pulsating and how you can fix the pulsation.

Key Takeaways:

  • Troubleshoot pulsating issues to understand the root cause. Refer to the manual.
  • A clogged or damaged nozzle is a common cause of pulsating.
  • Inconsistent water supply can lead to pulsation. Ensure adequate flow.
  • A faulty unloader valve affects water pressure and causes pulsating.
  • A dirty or damaged inlet screen reduces water flow and causes pulsating.
  • Spray gun defects like a bad trigger can cause pulsating.
  • Blocked pressure hose or air leaks reduce pressure and cause pulsating.
  • Trapped air in the pump leads to vibration and pulsating.
  • Check the water supply and supply hose for blockages.
  • Inspect and clean or replace a worn nozzle.
  • Clean the inlet screen thoroughly.
  • Check the pump and components for damage.
  • Regular maintenance prevents many pulsating issues.
  • Pulsating often indicates the need for cleaning or part replacement.

Importance of Power Washer Troubleshooting

A power washer is the best equipment for removing dirt and stains from outdoor surfaces like patios, cars, and driveways. It uses pressure water from a hose to remove the dirt. But like any other tool power washer can also encounter problems. 

Troubleshooting is very important to know about different causes of power washer pulsating. Troubleshooting helps you to understand the main reason for the pulsation of your power washer. It is suggested first to troubleshoot the problem causing the power washer to pulsate. Refer to your power washer manual for specific troubleshooting tips and tricks. This article will discuss some common causes of power washer pulsating and steps to overcome these causes.

Causes of Power Washer Pulsating

Power washers can pulsate due to several different reasons. The pressure washer can pulsate due to various reasons. There can be kinks, leakage, or blockage in other parts of a power washer. Some power washer components may need to be repaired or worn out.

However, the pulsation of the power washer can be easily fixed through some simple steps. We will have a look into these steps. First, let’s take a deep look into different causes of power washer pulsating.

Dirty or Clogged Nozzle

Why is My Power Washer Pulsating

The spray nozzle in a power washer is responsible for regulating water pressure. If the nozzle is dirty and clogged, it will affect the water pressure. Due to a clogged nozzle, the water will not come out with maximum force. The nozzle of the power washer can be blocked with dirt and debris particles. The clogged nozzle is one of the most common causes of power washer pulsation. Also, the nozzle can be worn out or damaged, which also causes power washer pulsation.

Inconsistent Water Supply

Pulsation of power washers can occur if the power washer is not getting sufficient water supply. The water supply must provide a consistent water flow to the power washer for proper working. Insufficient water supply can form air pockets in the pump, which causes pulsation. The inconsistent water supply causes the water pressure to fluctuate. The fluctuation, as a result, causes pulsation of the power washer.

Faulty Unloader Valve

The unloader valve in the power washer is responsible for delivering pressurized water after squeezing the trigger. The increase and decrease in the power washer are caused by the spring. When the spray nozzle is blocked, the unloader is in charge of releasing water pressure. 

Increasing or decreasing the water pressure will be difficult if the unloader valve is faulty. You can find the simple steps below to fix the defective unloader valve.

Damaged or Dirty Inlet Screen

A power washer can pulsate if the inlet screen inside the water inlet is damaged or accumulated with dirt. The inlet screen is a small mesh filter inside the water inlet connection of the power washer. The function of the inlet screen is to filter out the dirt from the water supply. 

If the dirt is not removed from the inlet screen, then after some time, it will become clogged with dirt and debris. The combined dirt and debris in the inlet screen will reduce the water flow pressure. A dirty inlet screen can cause pulsation, so it must be cleaned regularly.

Spray Gun Problems

Why is My Power Washer Pulsating?

The spray gun releases the pressure water from a power washer. If the spray gun fails, the power washer starts pulsating. The reason behind spray gun problems can be a defect in the trigger or the nozzle can be worn out. Check the spray gun’s trigger and lock. If it is not working correctly, try to exchange it with a new one.

Pressure Hose Blockage or Air Leakage

Why is My Power Washer Pulsating

The blockage of the pressure hose can cause pulsating of a power washer. It can be blocked with small dirt or grim particles interrupting the water pressure. Similarly, air leakage from different components can also cause pulsating of power washers. A leak in the hose, fittings, and other power washer parts can cause Air to enter the system. The air leakage causes a pressure drop and leads to pulsating of the power washer. 

Failure of Power Washer Pump

It is a big problem and can cause the pulsation of power washers. But you need not worry as you can fix this problem easily. Air can become trapped in your pump, causing vibration of the power washer. You can set it up by turning off the power washer and removing the hose. Let it sit for 20-30 seconds. At this time, the water will come out of the hose, and you can assemble it again for work. The pulsation will stop after doing this step.

How to Fix Power Washer Pulsating?

As you know about the causes of pulsation in your power washer, let’s discuss some simple steps to overcome power washer pulsating.

Take a look at the water supply

It is the most common cause of the pulsation of a power washer. Ensure that the water supply is turned on and the hose has no leaks. It would help if you increased the water flow as the water supply can be insufficient.

Check the water supply hose

Make sure that the water supply hose is not blocked with dirt particles. If you find dirt particles in the hose, clean it and operate the power washer.

Look over the spray nozzle

Inspect the spray nozzle because it can be damaged or worn out. The damaged spray nozzle causes pulsating in the power washer. You can easily remove it with the help of a small brush. You should replace it with a new one if it is damaged.

Clean the inlet screen

You can easily remove the inlet screen and clean it deeply. Cleaning can be done with the help of a small brush or toothpick. A clean and functioning inlet screen will improve pressure and water flow. It is also efficient for reducing the pulsation of power washers. 

Check up the pump of a power washer

Check the pump thoroughly for any signs of damage. Inspect the valves, seals, and other components for any signs of blockage and damage. The pump is mainly responsible for generating high-pressure water jets. It is also known as the heart of the power washer.

Regular maintenance of the power washer prevents pulsating and other problems. Cleaning the machine after every use and replacing damaged parts is the best way to overcome the power washer pulsating. 


Pulsating in your power washer can be a sign that it requires cleaning. Pulsating occurs when the different parts of the power washer are clogged with dirt or have kinks. If minor problems cause pulsating, you can easily fix them. But if the issue is big, replacing your power washer with a new one is suggested. Damaged and worn-out parts of the power washer also cause pulsating. In our article, you will find all the causes that are the reason behind pulsating. We have also mentioned the tips and tricks to avoid pulsating in our article.

Frequently Asked Questions

Why does my pressure washer keep surging?

Surging occurs when the pressure rapidly fluctuates, often due to insufficient water supply. Factors such as a clogged nozzle or air in the water can also contribute to this issue. To resolve it, thoroughly clean or replace the nozzle, remove air from the water supply by briefly turning it on, ensure an adequate water supply, and adjust pressure settings according to the manufacturer’s manual.

How do I fix my pulsing Karcher pressure washer?

If your power washer pulsates during use, it may be due to blockages in its components. To resolve this issue, clean the parts with warm soapy water and rinse them with cold water. Power washers typically vibrate to some extent, especially if water pressure is low, stemming from the motor or engine.

Why is my pressure washer revving up and down?

Revving up and down in gas pressure washers can be attributed to several factors, primarily fuel-related issues. Problems, like blocked fuel filters or poor fuel quality, can lead to fluctuations in engine performance. Checking for fuel blockage and replacing it if necessary can resolve this issue. Another potential cause is a faulty unloader valve, which can be inspected and replaced if required.