Updated at: 06-05-2022 - By: Helen Skeates

What’s wrong with my pressure washer? Difficulties such as dirt in its pump, air in its system and worn pump as well as problems like hot water in the cold water kind of pump, motor problems, seized pressure pump and unloader valve issues can occur while using a pressure washer.

As it stands, however, the pressure washer pump may be unable to deliver consistent pressure. Because anything is possible, it could lose its pressure or produce a low volume of water. As a result, examine its components and, if issues persist, consult the handbook.

How to diagnose low pressure on a pressure washer?

You must first determine the sort of pressure you are receiving in order to detect low pressure on a pressure washer. Make sure the pump is in good working order if the pressure is pulsing. If your water pressure is fluctuating, look for air leaks in the pump inlet and double-check that your water source is supplying adequate water. Pump hunger and a loose belt could be the cause of low pressure that persists.


We’ll walk you through the process of diagnosing low water pressure in your pressure washer in the sections that follow. Pulsating, constant, and unstable low pressure are all examples of low water pressure symptoms. In order to determine the source of low pressure, we must first examine each component individually.

● Low pressure and Pulsating

Cavitation, or pulsating low pressure, resembles a spray gun’s strong vibration during pressure cleaning. In most cases, this fluctuating low pressure is the result of a faulty pump. Pressure is being reduced because the cylinder of your pump isn’t producing enough pressure and is misfiring.

– Diagnose: Check the pump

First, inspect the head of the pump to see if there is a problem with it. If there is no obvious damage, look for any dirt blockage in your machine’s valve. Check the inline filter as well, as dirt and debris can accumulate inside the inline filter over time and become problematic after only a few washings. Consequently, your pressure washer operates at a low pressure level.

After removing the dirt and debris from the pump valve, inspect the seals for excessive wear. Make sure there is no water leakage by inspecting the piston seals. As a result, the low pressure could be caused by a problem with your seals.

● Unsteady low pressure

It’s basically the nozzle’s water pressure being lower than normal, which is what causes low pressure. It’s possible that the pressure will go from low to high in an instant. Water intake system problems or air buildup in the intake line may be to blame for this fluctuating low pressure.

– Diagnose: Check the pump inlet

This low water pressure can be diagnosed by first checking for any air leaks. To accomplish this, make certain that your water supply has enough water to completely submerge the pump’s entrance. Also, make sure that the chemical injector is completely closed and that no air is entering the intake line.

Give the hose points a good shake to see if there are any cracks. Hose barbs that are weak or damaged are more likely to bend or break. Once the suction lines have been thoroughly examined, look for any cracks or damage caused by heat. Finally, disconnect the water supply’s feed line from the hose and connect it to the hose. You don’t need to use a pressure washer to check for leaks because the hose pressure will do the job.

● Steady low pressure

Steady low pressure is the result of a pressure washer operating at a lower than normal pressure. There are a variety of possible causes for this issue, and you can narrow the list down by following the procedures listed below.

– Diagnose: Pump starvation

One of the most common causes of low water pressure at the machine’s exit is pump hunger. The intake lines should not be kinked or clogged and the pump should be supplied with enough water. The pressure washer won’t work at regular pressure if the hose is broken or kinked.

– Diagnose: Loose belt

If your machine’s belt is slack or slipping, the water pressure decreases. The belt can be tightened or replaced to resolve this issue.

Why doesn’t my pressure washer have any pressure?

A faulty pump, engine malfunction, or a broken motor are the most typical causes of your pressure washer not working. A faulty spark plug or hot water in a cold water pump might also cause your pressure washer to lose its power.

In the event your pressure washer is producing low or minimal pressure, it may indicate that some of the pressure washer’s components are malfunctioning. You don’t need to hire a professional to fix your machine if you can figure it out on your own.

● Reason 1: Spark plug (gas pressure washer only)

Even if your pressure washer’s gas engine is functioning, if it makes an unusual noise, you should have it checked out right once. Low- or no-pressure output is also an issue. Check the spark plug on your machine first. Check the spark plug wires for looseness and tighten them if necessary. It’s also a good idea to check the plug’s edge for corrosion. You can use a brush to remove the corrosion, but if it’s widespread, you’ll need to replace the power plug.

● Reason 2: Carburetor problem (gas pressure washer only)

You should check the carburetor if your engine isn’t running properly, even if your spark plug appears to be fine. In order to get the best out of the engine, it needs to be clean. Throttle failure is an obvious indicator if your car won’t rev higher. Dismantle the carburetor and use carburetor cleaner to thoroughly clean it. Make sure that you don’t use stale gas in your vehicle. Gas that has been sitting around for several months is considered bad gas. If you won’t be using gas for an extended length of time, consider adding fuel stabilizer to your mix.

● Reason 3: Air filter (gas pressure washer only)

A dirty air filter might also be a factor in the engine’s inability to perform at its best. Remove and inspect the air filter. Replace or clean it if it’s unclean. It’s time to get a new paper air filter.

● Reason 4: Hot water in a cold water pump

Pump damage may also be the cause of a lack of pressure in your pressure washer. In some cases, cold water pressure washers are the only ones that can be utilized. These pressure washer pumps can be damaged by exposure to hot water, resulting in poor washer pressure. Replacement of the pressure washer pump may be the sole option in this situation.

● Reason 5: Damaged pump

Pressure washer pumps can be damaged by using the wrong type of oil or lubricant, or by running the machine with unclean oil. Your pressure washer’s oil must be checked and replaced on a regular basis. An oil filter keeps the engine’s oil clean while it’s running. It is not present in a pressure washer pump. Oil needs to be changed whenever it becomes contaminated. Pressure washers with a closed-loop pump oil system can be found on the lower end of the market. The oil cannot be replaced in some machines.

Your pressure washer will overheat if you don’t add any water to it. The pump is cooled by water. A worn pump can be caused by overheating. Pump replacement is required in this situation.

● Reason 6: Motor malfunction (electric pressure washer only)

A pressure washer’s electric motor is the source of the high water pressure generated by the pump operations. The pressure washer will lose pressure if the motor fails. To see if your electric pressure washer’s motor is functioning properly, simply press the trigger a few times. if your pressure washer is capable of producing high and low pressure, the engine is in good shape.

How do you fix low pressure on a pressure washer?

Changing the oil and cleaning the filter is the first step in repairing your pressure washer’s low pressure. If your washer’s pressure still isn’t rising, make sure the water supply hose isn’t kinked and that the unloader valve is set to the pressure you want. Low pressure is frequently the result of a worn-out pressure washer nozzle. The nozzle on your pressure washer can be swapped out to resolve this issue.

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● Solution 1: Maintenance of your pressure washer

Maintaining your pressure washer is the first step in resolving low pressure issues. In order to get the most out of an equipment, regular maintenance is a must. Both gas and electric pressure washers fall under this category. In comparison to electric pressure washers, gas pressure washers require far more upkeep.

Your washer’s low pressure can be fixed by inspecting your engine and pump, and for gas pressure washers, the engine. Regularly inspect and replace the oil in your vehicle. The pressure washer’s filter is capable of capturing a significant amount of dust during cleaning. The pressure may drop gradually as a result of this. Check and clean your washer’s input filter on a regular basis. Also, check to see if the nozzle you’re using is deteriorating. To test whether there’s a difference, try using a different one.

● Solution 2: Fixing the hose

To determine if your pressure washer is still unable to produce adequate pressure, you should first check and replace the oil, filters and the nozzle. A minimum flow rate of 0.9 gallons per minute is required by the majority of pressure washers.

Supply hoses with a diameter of 34 inches or more are generally recommended by professionals for use in maintaining proper pressure. You may need to examine the line for any obstructions that may be lowering the washer’s pressure. Check the supply by disconnecting the hose from the inlet valve. Also, clean the inside of the inlet filter of dust and dirt.

● Solution 3: Replace the nozzle

Replacement of the end of the trigger wand’s nozzle is an alternative way to fixing low pressure. Occasionally, the nozzle wears out, causing the water to shoot in an unexpected manner. Low pressure can also be caused by an old nozzle that has holes that enlarge over time. Because of this, the water’s pressure lowers as these holes enlarge. With regular use, nozzles will degrade and eventually need to be replaced. Having a variety of nozzles on hand is a good idea. When the pressure drops, it’s easy to change the nozzle and determine if it’s because of the nozzle or because of something else.

● Solution 4: Adjust the unloader valve

The unloader valve’s primary job is to direct pump water toward the bypass. Low water pressure can be caused by the unloader valve.

If the nozzle replacement didn’t help, we’ll need to inspect the unloader valve as well. Small adjustments can be made to the pressure washer to boost its output. When adjusting the unloader valve, connect a pressure gauge to guarantee safe pressure. When making adjustments to the unloader valve, make sure the machine is running and that the water is flowing through the system. It’s possible that the valve is faulty. That’s when it’s time to get a new one.

Signs That A Pressure Washer Pump Is Damaged

A faulty pressure washer pump might exhibit a number of symptoms. Pulsating output pressure, a leak, and low output pressure are all typical signs. The most common cause of pump seal failure is a leak. Pressure pulsing is a symptom that there is not enough water in the pump.

Chances To Fix Pressure Washer Pump

Even if you want to use any other pump, the pump is essential. It’s just not right. Determine if the pressure washer has a triplex pump or an axial pump, or a combination of both. Simply said, the axial cam pump is less expensive. PSI, which handles the majority of house repairs, is also a result of this change. One of the issues with these products is that they don’t last all that long. How to start a pressure washer is explained here.

Life Expectancy Of Pressure Washer Pump

Pressure washer pumps are expected to last between sixty and one hundred hours on a single charge. The pump life of a higher-quality pressure washer, on the other hand, can reach 500 hours. A water pressure washer, on the other hand, is used on average by a household for fifty hours per year.

8 Things You Can Clean With a Pressure Washer

Under Pressure

You may use a pressure washer to clean the exterior of your home and other outdoor surfaces, whether you buy one or rent one from a local hardware store. When using a pressure washer, be sure to follow the manufacturer’s directions carefully and select the suitable nozzle. Are you all set to clear the way? Using a pressure washer, here are the eight best things to get rid of grime.


A good pressure-washing session is in order if the vinyl siding on your home appears faded or even dirty. Make sure to lower the psi (pounds per square inch) of the pressure washer to avoid damaging your siding. Keep the pressure low when pressure washing wood or aluminum siding to avoid denting aluminum or chipping paint off wood.

The Driveway

Sticky shoes, rain, leaking fluids, and dust from surrounding roads can degrade the driveway’s surface and leave it unclean and mottled. This can happen over time. Start pressure washing at the top of the driveway and work your way down to the apron to remove accumulated dirt and oil.

The Garage Floor

Your garage’s floor is probably stained with oil stains and filth from years of use even if you don’t spend much time there. Apply a degreasing solution to the floor and use the pressure washer on a low setting to thoroughly clean it. Switch to a higher setting and rinse off the solution after allowing it to sit for a few minutes (according to the manufacturer’s directions for this).


Have your deck’s aesthetics been tarnished by filth, dust, and debris? It can be revived with a good pressure wash. In order to avoid damaging the wood, set your pressure washer to a low setting (500 to 1,200 psi, depending on the type of wood).


While a beautiful wood or vinyl fence can greatly enhance the look of your home’s exterior, it’s important to keep it clean and free of dirt, mildew, and algae as time goes on. Pressure-washing your fence may make it look new again, whether you’re preparing to put your home on the market or just looking to freshen things up for spring. Hardwoods and vinyl can withstand more pressure, so use a lower setting on softer woods to prevent splintering and other damage.

Outdoor Furniture

Come spring, your outdoor furniture will appear a little scruffy if you didn’t have a place to put it in your garage or shed throughout the winter. Be sure to test a tiny, unnoticeable section first to avoid damaging the surface of your patio furniture with a low-pressure wash before the barbeque season begins.

Garbage Cans

There are a lot of stinky wastes in your garbage cans, including meat scraps, rotten vegetables, and more. While it may be tempting to put this work off, you will eventually have to clean them. Use a low-pressure washer with a scrub brush attachment to apply detergent and then rinse it off quickly to complete the task.

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Garden Paths

Moss, algae, and grime can tarnish the appearance of your once-pristine garden walks. Protect any adjacent plants with a tarp or other covering before using your pressure washer to clean them.

Clear It Away

Pressure wipe away the accumulated filth and grime.

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It’s A Wrap!

If my pressure washer isn’t producing enough pressure, there are numerous possibilities. And, as previously stated, they’re frequently encountered, much like pump dirt. Alternatively, it could be that the vehicle’s engine is unable to throttle up. But if you’ve already figured out what’s wrong, you’ll have to keep looking for the root cause. It’s better to deal with it in accordance with the previous suggestions!