For any kind of domestic or professional cleaning Karcher pressure washers are truly remarkable. However, these exceptional creations are still machines that can have several issues.

So, what are the common Karcher pressure washer problems?

Low pressure, water & oil leakage, running rough, and pulsation are the most notable issues. Moreover, you might even face problems with starting the washer on some occasions. The good thing is, that you can solve all of these problems easily by following the instruction manual and troubleshooting guide.

Can’t find the problem you’re facing with your unit? Don’t worry as we have more to cover!

6 Causes of Karcher Pressure Washer Common Faults!

Is your Karcher pressure washer finding it hard to start? Or, there’s no pressure while cleaning? The problems can be head-scratching, however, the causes might not be so hard to understand. Here’s why the problems arise:

Low or No Pressure

The pressure of your pressure washer can be significantly reduced due to clogged nozzles or filters, worn seals, inadequate water supply, and more.

These are not even the full extent of why the low pressure of your Karcher washer occurs. A leak in the system can increase the air inside the component and reduce the optimal pressure output.

Lastly, depending on your usage, seals and nozzles can get damaged and reduce the water pressure.

Water Leakage

If you ever thought about the possibility of running a pressure washer without water, then you should never think about it! Water is essential for your washer to function properly. 

That’s why you should definitely know when your Karcher pressure washer is leaking water. Mainly the problem arises because of damaged O-rings or seals. Moreover, your hose connector can get loose or it can be cracked as well.

So, those are some of the reasons why water leakage can be noticed on your Karcher pressure washer.

Heavy Pulsation

Due to the heavy piston action, your Karcher pressure washer includes a pulsation dampener. However, after a long time of usage, that dampener can get worn off or damaged.

On top of that, your valve seat surfaces can get filled up with debris, dust, and scraps. Those are definitely the primary causes of why you can notice unhinged pulsation and heavy pulsation.

Rough Running

Is your pressure washer giving you a hard time staying stable? One of the key reasons for that is your water flow. Turbulent water surging through your pump can rampant waves inside your pressure washer.

Similar to heavy pulsation, running rough situations can also be caused by debris and scraps inside your pump and valves. So, you can avoid two issues at once if you keep your valves clean!

Starting Problems (Applicable for Only Electric Models)

First of all, for any electric Karcher pressure washer, the power supply should be appropriate. Otherwise, it’s very easy for your washer not to start. The ignition of your washer is fueled by the spark plug. So, those little plugs can also be the cause of your headache.

In most cases, the starting problem can be solved easily if anything inside is not damaged. So, you won’t need to worry about this once you know how to reset the washer.

Chemical Not Dispensing

Before you identify the problem, you should know about which chemicals you can use with your washer. You can use dish soap in your pressure washer in some but not all of them. 

So, check if using the wrong chemicals has caused the issue. Then, you need to be careful about whether you’ve emptied out the detergent tank. Because without any detergent, what is the washer supposed to dispense?

Finally, finish off the inspection with clogged filters and valves.

How to Troubleshoot Karcher Pressure Washer?

It would’ve been so nice if knowing the problems would solve all of the issues, right? Well, in reality, you need to either fix it yourself or call someone to fix it for you. 

So, here are all the troubleshooting guides for every popular problem regarding Karcher pressure washers:

Low-Pressure Troubleshooting

First of all, check if you have the right-sized nozzle applied with your Karcher washer pressure. Often, users don’t realize that they have the wrong nozzles and filters which causes the pressure to be quite low.

You can easily change the nozzles by getting a replacement. Similarly, inspect your pressure gauge. In some systems, a pressure diagnostics sensing port is available to check the system pressure.

Use high-quality glycerin-filled gauges that come with snubbers to get proper pressure on your unit. 

Lastly, make sure you have a steady flow of water running through your pump. 

Water Leakage Troubleshooting

Fix Your O-rings

Plunger Replacement

Water leakage can be easily fixed by assessing these three components:

  • The O-rings and seals on your pump.
  • Plunger
  • Connection between hose and washer.

You don’t even know how many users have fixed their water leakage issues by inspecting these components and replacing them.

So, tighten any loose connection and look for cracked or broken seals/plungers on your pressure washer.

Heavy Pulsation Troubleshooting

When was the last time you cleaned your valve properly? If it seems hard to remember, then you already know it’s time to clean those nasty valves. 

On several occasions, we found out that pulsation in your pressure washer stems from debris and contamination.

Free up your busy schedule and clean everything that seems dirty enough. However, don’t go on and rub the surface out of the components. Be thorough but careful.

When the cleaning does not work, then you should definitely change the pulsation dampener. Because of the continuous effort of the dampener, the pulsation remains unnoticed. 

We would also suggest you check the bladder for rupture. While that’s the very last thing on the list, you should do a full inspection to be sure.

Rough Running Troubleshooting

We think you’ve already understood half of the troubleshooting by reading the cause. Because if the running rough situation is caused by turbulent water, then you just need to pass through steady water flow through your washer. 

Well, for some, that’s not enough to solve the issue.

Inspect the inlet line that seems to be loose or needs to be re-taped. Or, there can be several obstructions in the line of inlets. You should carefully re-tape the loose lines and remove the obstructions.

Lastly, you can inspect the high-pressure seals and replace them to ensure a better output without any roughness!

Starting Problems Troubleshooting

Before anything, double-check the power connection to your connection. In some cases, the wire connection can come loose due to wear and tear. Furthermore, check if there’s any problem with the fuse or safety switch.

If those are not the causes, then there’s one last thing to attempt!

As mentioned before, you can solve most of the power-related issues by simply resetting the washer. Now, how to reset the Karcher pressure washer?

For the Ground Fault Circuit Interrupter (GFCI) outlet, make sure that it hasn’t been tripped. Press the reset button on the outlet before turning the pressure washer on.

However, Karcher’s on/off switch problems can’t be solved this way. The same goes for if your washer motor has been damaged heavily.

For those, you should definitely contact the official support and get professional assistance.

Chemical Not Dispensing Troubleshooting

If you have any chemical that is not permitted by Karcher, then you should immediately discard that from your dispenser. You should always follow the manual to check which detergents work well with your specific model.

Wash the pump properly and then refill the tank optimally. It should be enough to make your detergent dispensing mechanism work again.

While knowing how to troubleshoot is great and all, your focus should always be on maintaining your pressure washer. Without proper care, any electrical appliance is bound to get broken easily.

Hence, prioritize ensuring routine maintenance rather than fixing the problems after the damage has been done!


Why is my Kärcher pressure washer not making pressure?

The pressure of your Karcher pressure washer depends on the pump and water pressure. Check whether your pump is clear and your water pressure is stable and non-turbulent.

Where can I find Karcher pressure washer replacement parts?

You can find Karcher pressure washer replacement parts in most tools and equipment stores. Or, you can look for Karcher stores in your locality to get the authentic parts without worry.

Are Karcher pressure washers repairable?

Yes, most of the electric Karcher pressure washers are repairable. You can get replacement parts from any online or offline store. However, make sure you purchase original Karcher products for better compatibility.


There you have it. Your complete solutions to everything related to Karcher Pressure Washer problems. Now, you should be able to identify the underlying causes and fix any issues easily.

However, always contact professionals and Karcher support if you can’t fix the issue yourself!

Victoria Peterson

I am a passionate gardener who wants to help you create and maintain your dream yard. I know that it can be daunting to take on a project like this, but I am here to help. I have been gardening for years and have learned a lot along the way. I want to share my knowledge with you and help you create the perfect yard for your home.

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