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Pressure Washer Troubleshooting Guide 

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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!

How to Fix Water Leaking From the Hose Connection

If you have water leaking from the hose connection, check the connection. There may be a broken or improper connection. Check this and connect it properly to solve the issue. On the other hand, you may have a broken or worn rubber washer. If so, it’s time to replace it. This should fix the leaking.


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
Cause Solution
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
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
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
Cause Solution
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
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
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
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 the 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
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
Cause Solution
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
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
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
Cause Solution
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
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
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
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
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
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
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.

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.

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 20-something 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!
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