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Pressure Washer Troubleshooting Guide 

Updated
Don’t let your pressure washer cause you trouble. 

Is your pressure washer acting up? With any type of power tool, issues can arise. We’ll walk you through a bunch of common issues and show you the best way to troubleshoot the problem.

Whether this is for gas pressure washers, electric pressure washers, water pressure issues, leaking issues, or something else — we have a ton of fixes you could try to solve a variety of problems.

By the end, your pressure washer should be back in perfect working order!

Key Takeaways

  • Troubleshoot common pressure washer issues, including gas and electric pressure washers, water pressure, and leaking problems.
  • Fix water leaking from the hose connection by checking the connection and replacing a broken rubber washer if needed.
  • Address gas and electric pressure washer issues, like the engine not starting or stopping while in use, by checking gas levels, oil levels, and electrical connections.
  • Solve water pressure problems, like low or pulsating pressure, by inspecting and cleaning components such as inlet valves, manifolds, and nozzles.


Gas Pressure Washer Issues

First, let’s look at some of the common problems users encounter when using a gas pressure washer.

Pressure Washer Not Starting

If your pressure washer isn’t starting at all, this could be down to a few factors.

No Gas

Check the gas levels on your pressure washer. If there is no gas or low gas, fill it up with gas.

The Choke Is In the Wrong Position

Check your user manual and move the choke to the recommended position.

Pressure Build-Up

There may be pressure build-up in your gas pressure washer. Squeeze the trigger gun to release the built-up pressure in the system.

Disconnected Spark Plug Wire

If your spark plug wire is disconnected, simply reconnect it and your pressure washer should start.

Faulty Spark Plug

You possibly have a faulty spark plug. In this case, you should replace it with a new one.

Engine Stops While In Use

Maybe you’ve got your pressure washer to start, but it stops while you’re using it. There are some easy fixes for this issue.

Low Oil Level

This could be down to low oil. Most gas pressure washers automatically shut down when the oil gets too low. Check the oil and fill it up if necessary.

Dirty Air Filter

If your air filter is dirty, try cleaning it out. If that doesn’t work, replace the air filter with a new one and try again.

Oil Leaking From the Engine

This can be an alarming problem, but thankfully there is a fix to prevent the issue.

The Seals Are Worn

If oil is leaking from the engine, it’s mostly due to worn-down seals. You will need to replace the seals with new ones. Check with the manufacturer as this may be covered by the warranty.


Electric Pressure Washer Issues

Let’s look at some of the issues that electric pressure washers bring and how to fix them.

Pressure Washer Won’t Start

If your pressure washer isn’t starting at all, there may be some easy and quick fixes.

Faulty Electric Outlet

It could be that your electrical outlet is faulty. Check the main fuse and check the plug. If there is an issue with that outlet, call an electrician and use a different outlet in the meantime.

Pressure Washer Isn’t Plugged In

We’ve all been there… Why is our electrical appliance not working? Oh, we forgot to plug it in! Double-check if your pressure washer is plugged in. Your fix may be as simple as this.

Check the Reset Switch

Some electric pressure washers have a reset switch that you need to press once you’ve plugged the pressure washer in. This is required to power up the pressure washer.

Faulty Motor

It could be a bigger issue, like a faulty motor. If you’ve found that nothing else works, then check in with your manufacturer and get a replacement if you’re still within the warranty period.

Engine Stops While in Use

If your electric pressure washer engine is stopping during use, we have one hack you can try to fix it.

Low Voltage

If the engine is stopping while in use, it’s likely down to low voltage. You must check the voltage is within the motor’s specified range. If changing this doesn’t work, check in with the manufacturer to see if they have any advice or if it could potentially be a faulty motor.

No Water Pressure

Water pressure itself may be an issue for you. There could be a few things causing this issue, and we’ll look at the best ways to troubleshoot the problem. If there’s no pressure at all, this could be down to two issues. Let’s look at the best ways to fix this problem.

Damaged Unloader Valve

If your unloader valve is damaged or worn, adjust the unloader screw and check for any damaged seals or springs. Replace what needs to be replaced.

Damaged Pump Inlet Valves or Manifold

If your pump inlet valves or manifold are damaged, disassemble the pump and replace or clean the components of the inlet manifold.

Low Water Pressure

If low pressure is an issue, this could be down to a variety of factors.

Insufficient Inlet Water Supply

You may not be getting enough water supply. Check your hose isn’t kinked. Then ensure full water pressure is coming from the tap. Also, check your manual to check that you are using the correct diameter of garden hose.

Blocked Inlet Water Filter

Check your garden hose connection for a blockage. Remove any debris and enjoy much better water pressure!

You’re Using the Wrong Nozzle

You may be using the wrong nozzle — or no nozzle at all. Check you’re using the right nozzle.

Inlet Chemical Injector Valve Is Open

If you’ve left the chemical injector valve open, and the detergent pickup tube isn’t in detergent, then it can draw air up the detergent line. This leads to low water pressure. Either put the tube into detergent or close the injector valve.

Dual Lance Wand Valve Is Open

You must keep these valves closed when using a high-pressure nozzle if you want to avoid low water pressure.

Leaking Seals In Pump Manifold

If your pump manifold seals are leaking, you should replace the seals to achieve better water pressure.

Pulsing Pressure

Besides low or no pressure, you also might find your pressure washer has pulsing pressure. Let’s look at the best way to solve that issue.

Damaged Pump Inlet Valves or Manifold

Similar to the issue with no water pressure, this issue can lead to pulsating pressure, too. Disassemble the pump and replace or clean the components of the inlet manifold.

Faulty Pump

The pump could be faulty in which case you’d need to replace it. If it’s still covered by the warranty, contact the manufacturer and you should be able to get a free replacement.

Pump Sucking Up Air

If the pump is sucking up air, turn off the machine but maintain the water supply. Release the pressure by squeezing the trigger gun. Once this is done, check the water pressure again. It should be resolved.

Obstruction

It may be an obstruction that’s causing the pulsating pressure. This could be an obstructed nozzle in which case you should use a needle to clear the holes. It could also be down to an obstructed water inlet filter. In this case, use fresh water to flush the water inlet.

Lastly, it could be the gun or spray wand that is obstructed. Use vinegar to clear out any deposits.


Water Leaking Issues

There’s nothing more annoying than your pressure washer leaking. But there are some easy fixes that will save you from fully replacing your pressure washer.

Water Leaking From Pump

Let’s first look at how to troubleshoot the issue of water leaking from the pump.

Broken Seals

If water is leaking from the pump, it’s likely that the seals are cracked, broken or worn down. In this case, you’ll need to replace the seals or the entire pressure washer. Both should be covered by the warranty.

Loose Bolts of Pump Assembly

Check your pump assembly and tighten the bolts to ensure the pump casing is properly sealed together.

Thermal Valve Activated

Sometimes, activating the thermal valve can cause leaks. Wait five minutes before using your pressure washer. This will deactivate it to cool it down enough to prevent leaks.

Water Leaking From Hose Connection

What about if water is leaking from the hose connection? We can help.

Connection Issue

It could be that there’s a broken or improper connection. Check if this is the issue and connect it properly to solve the problem.

Broken Rubber Washer

If the rubber washer is broken or worn, replace it.

Water Leaking From Wand or Spray Connection

Let’s look at how to prevent water from leaking from the wand or spray connection.

Broken O-Ring

The o-ring inside the hose connection could be broken. You will need to replace the o-ring or return the hose for a new one. Check if this is covered by your warranty.

Not Connected Properly

Check if the connection is correct and if not, connect it properly.


Other Pressure Washer Issues

While those are the main categories, there is still a range of other issues you might face. But we’re here to put a fix to all of them so you can enjoy pressure washing with no issues.

Detergent Injector Not Working

The detergent or chemical injector can cause some issues. Let’s look at the specific reasons and the appropriate fixes.

Wrong Nozzle

If you’re using the wrong nozzle, this can cause the issue. Insert the black soap nozzle onto your pressure washer and voila, works as good as gold!

Clogged Filter

The soap tube inlet filter could be clogged. This is the hose that sits in the soap bottle. Check for clogs and flush with fresh water to remove debris.

Soap Inlet Valve Clog

The soap inlet valve may be clogged or blocked. This is the pump side of the tube. To fix this, remove the hose and use a small Allen key to push through the hole and remove the debris or unstick the ball valve.

Thick Detergent

The detergent mixture may be too thick, especially if you didn’t dilute it enough. Add more water to the solution and it should work a lot better.

Closed Knob

Make sure that the knob on the detergent injector is open.

Low Detergent Supply

Check you have enough detergent in your supply container. The tube needs to be fully immersed to get a good amount of detergent through.

Pressure Washer Too Noisy

No one — especially not your neighbors — wants to deal with a noisy pressure washer. We can help you fix that.

Water Intake Blocked

If the water intake is blocked, this can lead to excessive noise. Check for blockage and either clean or replace the water intake.

Oil Levels

There may not be enough oil in the engine or the pump. If it’s the engine, simply add oil. If it’s the pump, you must disassemble the pump to check. Add the oil as per the manufacturer’s guidance.

Oil Leaking From Pump

Uh-oh! An oil leak. Let’s look at potential fixes.

Loose Bolts or Fitting

This could just be down to loose bolts of fitting so tighten these up.

Damaged Parts

There may be damaged parts, such as the pistons or the seals. Thoroughly check for damage. You may need to disassemble some parts. Clean what needs to be cleaned, or replace the damaged bits. Some pieces may still be covered by your warranty.

Pressure Washer Pump Overheating

Let’s look at what to do if your pump is overheating.

Thermal Relief Valve

While the thermal relief valve is there to prevent overheating, sometimes it can do the opposite. The water can get trapped in the washer if you never turn this off, and fresh cool water can’t enter.

You should release the water by pulling the trigger every minute or so. Don’t keep the washer running if you’re not going to use it for a while as this can overheat your pump and cause permanent damage.

Pressure Washer Runs But Won’t Spray

What if your pressure washer is running but isn’t spraying? There are a few reasons why this could be and we have suggested fixes.

Trigger Gun Is Released

Squeeze the trigger on the gun to spray the water. This may seem obvious but sometimes you might forget!

No Water Supply

You may have turned the water supply off. Simply open the water supply valve.

Spray Tip Nozzle is Clogged

Clean out the pressure nozzle to remove clogs. If this isn’t possible, you may need to replace the nozzle.

Dry Pump

If your pump is dry, it needs to be primed. Your user manual should give you instructions on how to do this properly. In general, it is likely to involve cracking open the high-pressure outlet fitting on the pump until water flows out.

Trigger Gun Won’t Shut Off

If your trigger gun won’t turn off, this can lead to some frustrating problems. We’ll share a few potential fixes.

Debris in Valve Assembly

There could be debris in the gun’s valve assembly. In that case, clean out the valve assembly if possible. If not, you’ll need to replace the trigger gun.

Worn or Missing O-Ring

If you’re using quick-connect fittings, check the coupler between the trigger gun and the hose connection. Here you’ll find where the o-ring should be. If it’s missing, you’ll need to replace it. If it’s worn down, it’s also time for a replacement.

Pressure Washer Smoking

This is quite a serious issue. If you have white or black smoke, you’ll want to deal with that immediately.

Wrong Fuel

You may be using the incorrect fuel type, or you may have accidentally put water in the fuel tank. Drain the fuel tank and replace it with the correct fuel.

Improper Air Adjustment

Adjust the air bands on the burner assembly to provide the correct fuel-to-air ratio.

Caution

We recommend replacing the coil insulation before doing this. The unspent fuel can saturate the insulation and potentially cause a fire in the heating coil burning chamber. When in doubt, contact a professional.

Low Fuel Pressure

Low fuel pressure can lead to smoke, especially in hot water pressure washers as they require more than 140 PSI of fuel pressure for the burner to operate properly. Consult your user manual and adjust the fuel pump pressure to the correct specifications.

Build Up On Coils

There could be soot build-up on the coils. Clean them with a soot remover or contact a local repair facility to do this for you.

Improper Burner Nozzle

Check your user manual for the manufacturer’s requirements of the burner nozzle. Replace as and when needed.

Improperly Aligned Electrodes

If the electrodes aren’t aligned properly, the machine won’t produce the proper spark to ignite the diesel fuel. This will result in wasted fuel being sprayed into the burn chambers which can lead to smoke. Check the user guide for proper alignment specifications and replace the electrodes if needed.


Tips for Maintaining Your Pressure Washer

While being aware of these issues and fixes is all well and good, you can avoid these problems when you maintain your pressure washer well. Here are top tips for pressure washer care.

  • Check for clogs often: Clogs can appear in various different tubes, nozzles, tanks, and hoses. You should check often so that you can remove them before extreme damage is caused.
  • Examine your pressure washer for damage: Frequently assess your pressure washer for damage. You may find cuts, leaks, bulges, or other damage. Repair or replace anything that is broken.
  • Rinse out detergent: After using detergent, remove the tube from the detergent supply and set the spray to the lowest pressure. Run water through the system for a couple of minutes to clear out detergent residue.
  • Relieve the machine’s pressure: After use, turn off the pressure washer and the water supply. For electric machines, unplug it from the outlet. Run the pressure washer until the water stops flowing to let out any remaining pressure.
  • Clear out remaining water: For gas machines, pull the recoil handle six times to let out the remaining water. For electric machines, turn the unit on until the water leaves the pump. Then turn the machine off right away.
  • Winterize your pressure washer: If you’re not going to be using the machine for a few weeks at a time during the winter, make sure you winterize it. This will maintain the machine through the cold months.
  • Replace o-rings: O-rings need to be replaced when you notice signs of wear and tear, especially in high-pressure hoses and spray-gun connections.
  • Keep the pressure washer clean: Make sure your pressure washer is clean. This includes cleaning the exterior but it also involves making sure there is no debris in the vents, tanks, or hoses.

FAQs

Is There a Reset Button on a Pressure Washer?

Pressure washers do have a reset button that you can depress when the washer cuts out. If it doesn’t restart after pressing the reset button, you may have a more serious issue with the pressure washer.

Where is the Unloader Valve Located on a Pressure Washer?

The unloader valve is located between the pump and the hose. It is a safety device to protect the pump when there is pressure buildup while the trigger is disengaged.

What Does Unloader Valve Do on Pressure Washer?

Knowing what an unloader valve does on a pressure washer is vital. It is a device that protects the pump from excess pressure when the trigger is disengaged. When pressure builds, it gives it a means of escape.

Why Does My Pressure Washer Turn Off After a Few Minutes?

The reason why your pressure washer turns off after a few minutes is down to an air blockage in the system. Check the filters and pump for debris, and clean the nozzle.

What Happens If I Put Too Much Oil In My Pressure Washer?

If you put too much oil in your pressure washer you risk damaging the motor. It also creates lots of black smoke when you operate the pressure washer.

How Long Can You Continuously Run an Electric Pressure Washer?

Knowing how long you can continuously run an electric pressure washer is crucial if you want to extend its lifespan. Most pressure washer work in five to ten minute bursts.


Troubleshooting Tips

With this guide to pressure washer troubleshooting, you now know the fix to pretty much every problem that could go wrong. Whether that’s to do with gas pressure washers, electric models, water pressure, leaking, or something else, we have tons of fixes to try.

When in doubt, contact the manufacturer or a professional. In many cases, you’ll find that your warranty covers damage, meaning you don’t have to fork out cash to fix big problems.

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About the Author

Beth McCallum

Beth McCallum is a freelance writer & book blogger with a degree in creative writing, journalism, and English literature. Beth firmly believes that a tidy house is a tidy mind. She is always looking for new ways to sustainably clean and tidy her house, that's kind on the environment but effective in the house, too!