Ask anyone who has ever used a Karcher pressure washer – and they’ll vouch for its durability. Yet, after prolonged and regular use, you may find that your loyal and reliable cleaning buddy is not working correctly – or at all. Wait! Don’t think about buying a new pressure washer yet!
A Karcher pressure washer may not turn on or keep cutting off once it’s on. It can also fail to apply pressure and clean properly due to insufficient power or water supply. It can also result from dirt, blockages, or air pockets in the system. It could also be because of a faulty pressure washer motor, pump, unloader valve, or other internal components.
While some of these can be easily fixed, others need a little more technical know-how. Let’s find out why your Karcher pressure washer might not be working – and how to fix it.
Most Common Problems with Karcher Pressure Washer
An aged and overused Karcher pressure washer may stop working or show performance issues, as mentioned below –
- The pressure washer won’t start;
- The pressure washer keeps cutting off and runs intermittently;
- Low or no water pressure;
- Water sputters out with small explosions;
- Attachments won’t spin or work.
Karcher Pressure Washer Not Working – Causes
If you experience one or more of the above problems, you need to identify the cause, which could be as mentioned below –
1. Insufficient Power
Inadequate power supply is a common problem that might prevent your Karcher power washer from turning on. It could be something as simple as an improper connection to the power socket or the power switch not being turned on.
Using an electric extension cable might also be the reason. That’s because the extension cord you are using might not be designed to handle the wattage consumption of your pressure washer and might be overloaded.
The machine might also not work due to a faulty or worn-out power cable, power plug, or other parts that regulate the electricity supply into your pressure washer. As a result of the above, the pressure washer may not start, keep cutting off, or deliver low pressure.
2. Poor Water Supply
Another common but often overlooked reason behind poor pressure delivered by the pressure washer is insufficient water supply. This means that the water source cannot deliver enough water to your pressure water.
In order to operate, your Karcher pressure washer needs water to flow at a specific rate. This is expressed as gallons per minute or GPM, and the details are available in your machine’s user manual. If the water supply falls below this rate, your pressure washer will not function.
3. Dirt Buildup
Over time, there might be a buildup of dust, dirt, or debris. They can develop in and around the inlet or outlet hose or valve, regulator, pump valve, gun, nozzles, O-rings, or other parts.
Buildups can reduce the pressure washer’s performance and cause the components to wear off. If left unattended, there might be internal damage.
4. Air Trapped in the System
Air blocks in the spray wand, hose, etc., can prevent the pressure washer from starting. It can also lead to poor pressure, as a result of which the pressure washer will fail to clean properly.
You may also notice inconsistent pressure, as water sputters out and creates little explosions while exiting the gun. The reason behind this is trapped air, which can damage the water pump.
5. Blockage
Any blockage or obstruction in the washer’s system can prevent the appliance from performing properly. It can be gunk in the valves, nozzle, inlet filter, etc. It might also be a kink or bend in the hose.
6. Leakage
Leakage is a common problem resulting from wear and damage. It can be found in the hose, attachments, valve, and other parts. The pressure won’t work properly when leaks occur in the water path.
7. Damaged, Worn, or Faulty Parts
Over time, the internal parts of the pressure washer can get worn out or damaged for various reasons, including frost damage. The machine then stops working. It can be a damaged switch, malfunctioning water inlet filter, faulty trigger gun, or worn-out motor or pump.
8. Hot Water Usage
Some Karcher pressure washers, like the Karcher HDS 7/16 C, are designed to operate with hot water. However, not every other Karcher model is engineered as a hot water pressure washer.
If you do not use cold water in any other model, the pump and other parts will be overworked, and the device won’t run. It can also lead to damage.
9. Incorrectly Fitted Parts
Your Karcher pressure washer has various attachments, like the high-pressure hose, nozzles, spray gun, patio cleaner attachment, and more. The appliance also needs to be connected to a garden hose or other water source.
If these are incorrectly fitted, e.g., there’s a loose hose connection or mismatching attachment, the machine won’t work. Wrong adjustment is also a problem in the internal parts, especially if the parts have been repaired or replaced.
10. Other Technical Problems
Your Karcher unit may have other problems, like a misaligned unloader valve, a malfunctioning pump, or problems in the motor or pump parts. These might be challenging to detect by visual inspection.
This is especially true if you’re not experienced in repairing an appliance. It’s best to avoid trying to disassemble the machine parts in that case – and take expert help instead.
Karcher Pressure Washer Problems – Common Fixes
Before you contact Karcher customer care to request repair services, it’s a good idea to inspect the machine yourself. There are some easy ways to fix the issues mentioned above and get your pressure washer working again. Take a look –
a) Fixing the Power Problem
The domestic Karcher pressure washers are mostly electric models. So if yours doesn’t turn on, ensure the power cord is plugged in and the switch is on. Avoid using an extension cord, as well.
If these are not the issue, and the machine still refuses to turn on, check the power cord and the plug for signs of damage. This is the most likely cause if the machine cuts repeatedly.
The power supply to your machine can also be obstructed by damaged micro-switches. You’ll need to open the machine to locate the micro-switches – and examine them by pressing them and checking for signs of damage.
These switches can be replaced easily to fix the problem. Here’s a video to walk you through the replacement process. However, since this step requires you to open the machine up, we suggest doing this only after external checks and fixes.
b) Fixing the Water Supply Problem
It’s essential to ensure that the water supply rate (GPM) does not match the pressure washer’s requirement. To check your GPM, take a 5-gallon bucket and place it under the faucet. Allow it to fill up – and count the time taken to fill the bucket (in seconds).
Let’s assume that the time taken is 17 seconds. The simple calculation to find your GPM is – 5 gallons / 17 seconds * 60 = 0.294 GPM.
To increase the GPM of the water supply, you can use a large pump. This is especially effective if you source your water from a well, pond, stream, etc. You can also adjust the GPM of your pressure washer using its regulator and attaching the right nozzle and quality detergents.
c) Fixing Inlet Area Problem
Check the inlet parts, including the water inlet filter, inlet hose, and inlet valve. See if these are blocked, damaged, or leaking.
If the inlet hose has blockages or dirt buildups, flush and clean it. If you find damage or a leak in it, you will need to replace it. Here’s a video to help you do that.
The inlet connector inside the machine is another part that may need some cleaning with the help of a brush or a piece of cloth. The replacement process is also easy.
Don’t forget to check its O-ring seal and ensure it’s tight and in place. Give it a quick clean to see if it can stop leakage. If the problem persists, or if the O-ring is damaged, you must change it.
Also, inspect the inlet filter that sits at the hose connection point. While cleaning a dirty filter is hassle-free, we suggest replacing it, especially if it has stubborn dirt.
d) Fixing Nozzle or Gun Problem
The nozzle of your pressure washer’s gun may need some cleaning to fix the problem of no pressure. That’s because it’s easy for dirt, dust, and other objects to get lodged inside its small channels.
As a result, you may find your Karcher round head not spinning or the dirt blaster or other rotary attachments not working properly. You can use a nozzle cleaner which is easily available.
But be careful not to end up damaging the nozzle while cleaning. Here’s a video that will help you with the cleaning of the round head if you notice your Karcher patio cleaner attachment not spinning.
Also, inspect the malfunctioning attachment to find a leak or damage. If it is uncleanable or damaged, you’ll need to replace the nozzle to get sufficient water flow and pressure.
The process is not complicated at all, as you have to attach the new accessories in place of the old ones. The washer gun may have the same problems as the attachment, i.e., it may have a blockage, damage, or hole. If cleaning the gun is not sufficient, you must replace it.
e) Fixing the Air Block Problem
An air block in the system, caused by leaks, loose valve seals, etc., can be detected by unusual noises, unnecessary vibrations, and lack of pressure. It can also prevent the unit from starting. And it must be taken care of as air in the power pump can cause severe damage.
Removing such a block is fairly easy, as you just have to let it “bleed” out. First, check the pathway and ensure that there are no leaks.
Make sure to fix any loose part that needs tightening to prevent air from seeping in again. Also, ensure that the pump of the unit will not be able to introduce air into the system.
Next, tighten the inlet connections and disconnect the gun or pump from the outlet hose. Now, turn on the water supply and allow the water to run through the machine. While leaving the system, the water will push out any air in the way – like this.
f) Fixing Motor Problem
The motor of the pressure washer power is the unit’s pump. The pressure washer may experience pressure problems if the motor starts malfunctioning. You may also find loud noises coming from it.
The simplest way to fix it is by replacing the pump. To do that, you will need to open up the pressure washer and locate the motor. Detach it from the machine and put a new motor in its place. Here’s how you can replace the motor.
g) Fixing Pump Problem
Another way to fix Karcher pressure washer problems is to clean the parts of the pump. This is yet another solution that requires a certain level of expertise. You’ll need to disassemble the pump and clean individual parts before reassembling it.
However, you should take the pump assembly apart only if you are confident and experienced. Otherwise, we would advise against it. But you can also choose to replace the entire pump assembly.
It is a much easier process as you need to remove the assembly from the pressure washer and place a new one into the unit. If you are confident enough to do that, you can follow this video for guidelines.
Final Words
If your Karcher pressure washer does not work, the solution could be pretty simple. Follow the tips we have mentioned to inspect the unit and detect the issue. Then, implement the solution that seems fit.
Try to detect and fix the issues externally as much as possible and avoid opening the machine. Also, pay attention to regular cleaning and maintenance of the pressure washer to ensure that it remains in top condition for a long time.
