The high-pressure cleaner isn’t producing enough pressure: what should you check?
Is the water jet less powerful, or does your pressure washer seem to have swapped its ‘tornado’ mode for a simple garden watering can? There are several possible causes for this loss of pressure. A blocked hose, a clogged filter, a worn-out pump… We’ll go through the possible reasons to understand why your machine is no longer working as effectively as before.
THE POTENTIAL CAUSES FOR THIS FAULT:
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Insufficient water supply or blocked filter
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Clogged or worn nozzle
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Damaged high-pressure hose
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Faulty motor
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Faulty capacitor
WARNING
Before you do anything to your appliance, make sure you disconnect it from the power supply.
There is a risk of electric shock.
Wear suitable protective gloves if you need to dismantle anything.
There is a risk of getting cut or injured.
The water supply is insufficient or the filter is blocked
Before carrying out any work, check the water supply. Insufficient flow or a tap that is not fully open may prevent the high-pressure cleaner from building up pressure properly.
Even with a proper water supply, the problem may lie with the high-pressure cleaner’s filter. Located at the inlet of the machine, it traps impurities (sand, limescale, debris) to protect the pump.
When it becomes clogged, it restricts the flow of water and reduces the flow rate, preventing the machine from generating sufficient pressure. Cleaning the filter often restores normal water flow and the machine’s performance.
The nozzle is blocked or worn
The nozzle concentrates and directs the pressurised water to form a precise jet. If it is partially blocked by dirt or limescale, the water no longer flows properly and the pressure is significantly reduced. As a result, the jet becomes uneven or less powerful. Cleaning the nozzle often solves the problem. If the nozzle is worn or misshapen, it is best to replace it to restore an effective jet.
Buy a nozzle for your high-pressure washer here
The high-pressure hose is damaged
The high-pressure hose is an accessory that is subjected to heavy use. Depending on the model, it is generally between 5 and 10 metres long, which makes it susceptible to kinks and twists.
Common examples of incorrect handling include a high-pressure hose that has been kinked, crushed (for example, under a wheel) or coiled too tightly after use. Leaving it outdoors, exposed to frost or direct sunlight, or storing it whilst still under pressure can also weaken the material and cause cracks or micro-leaks.
It is advisable tocoil it in wide loops, without twisting it, and to release the pressure before storing it. Even a slight leak results in an immediate loss of pressure.
If the hose shows visible cracks, a persistent leak or a weakened area, it is best to replace it to ensure the pressure is correct.
Buy a hose for your high-pressure washer here
The motor is faulty
The motor/pump unit of the high-pressure cleaner pressurises the water to ensure the appliance operates correctly. Fitted with an impeller, it may lose efficiency if an object blocks the impeller or if its blades are damaged.
In this case, the machine will still work but the pressure will remain low despite a sufficient water supply. Replacing the motor/pump unit will restore your Karcher, Nilfisk, Bosch or other high-pressure washer to full efficiency.
Buy a motor for your high-pressure cleaner here
The capacitor is faulty
The capacitor, also known as a interference filter, provides the electrical pulse required to start the motor. If it is faulty, the motor may struggle to start or fail to reach full power.
Your outdoor cleaning equipment may then operate at insufficient pressure or emit a slight humming sound without starting properly. Replacing the capacitor, which is an inexpensive spare part, often resolves the fault quickly.