Pressure Washer Troubleshooting? Get Started Here

Guidance to get your pressure washer running again

If your pressure washer quits working, the last thing you want to have to do is take it to a mechanic or order an entirely new unit. However, with some investigation (and some parts from The ROP Shop), you might just be able to fix the problem yourself, saving time and money.

We’ll walk you through some common problems you might be having with your pressure washer and how you can fix them.

Jump directly to your pressure washer’s issue by clicking one of the links below:

• Pressure washer isn’t producing pressure
• Pressure washer is surging
• Pressure washer is leaking
• Pressure washer isn’t turning on
• Pressure washer isn’t siphoning detergent
• Pressure washer is pulsating
• Pressure washer is running rough

Why does my pressure washer not produce enough pressure?

Let’s start with a common frustration you may have with your pressure washer: low (or even no) pressure.

The first potential cause is insufficient or restricted water supply. To remedy this, check your hose to remove kinks, and make sure that your tap is fully open. It’s also possible that the diameter of your hose is too small to provide adequate flow, and you’ll have to get a larger hose.

If this doesn’t work, it could be that your water inlet filter is blocked by debris. If it is, clean it out and see if that resolves the problem.

You can also check your water outlet pressure hose, gun and wand, and spray tips for obstructions. Alternatively, it could be that your spray tip has simply worn out, decreasing the water pressure.

Clean out obstructions or replace worn-out parts as needed. This is also a good time to check the threaded connections between your hose, gun, and wand for any leaks. If you find any, you can apply thread tape to help fix the issue.

Finally, check for cracks in your pump valves, inlet and outlet manifolds, and pump body. If you find cracks in the latter two, you will likely have to replace your pressure washer pump.

Why is my pressure washer surging?

Closely related to general low pressure is the issue of “surging,” where your pressure washer repeatedly sprays normally but then drops in pressure.

A surging pressure washer is probably due to insufficient water going into the pump. This means you’ll want to check your water source and make sure it’s turned on all the way and that there aren’t leaks or kinks in your hose.

Still surging? Check your inlet and discharge valves. They could be dirty or worn, so you’ll want to clean or replace them if needed. ¹

Why is my pressure washer leaking?

Sure, water is supposed to come out of your pressure washer…but not from just anywhere.

If you’re experiencing leaks in your pressure washer, it’s probably because one or more of the O-rings in your washer needs to be replaced. You’ll have to go through the various parts of your washer to identify the culprit and replace the faulty seal(s). ¹

If the problem isn’t a bad seal, check your hose, gun, and wand for leaks and apply thread tape to any connections that don’t seem secure.

Still leaking? Is it possible that water froze inside of it? If so, that’s a bad sign. Water expands when it freezes, and if it did that inside of your pressure washer, it could have caused cracks to form. You’ll probably want to take your pressure washer in to a professional to take care of it. ¹

Why is my pressure washer not turning on?

If your pressure washer’s engine won’t start, begin with a potentially simple fix: check the spark plug connection.²

If that fails, it could be that fuel has deteriorated your fuel lines and clogged your carburetor. You can resolve this by removing the fuel and cleaning the fuel system.

Why does my pressure washer engine start and stop?

Alternatively, maybe your engine does start but has trouble running continually. This could be due to any number of components becoming clogged, such as the fuel or air filter, the spark arrestor, the carburetor, or the fuel cap. Clean or replace those parts as needed and try again. ²

Why won't my pressure washer siphon detergent?

If your pressure washer isn't siphoning detergent, there are several steps you can take. First, make sure that your pressure washer is on the correct setting—to use cleaning chemicals in your washer, it should be on low pressure. This also means you should swap any extensions intended to create high pressure, like water nozzles, for ones meant to deal with detergents. ³

It’s also possible that you’ve forgotten to open the chemical valve on your pressure washer¹ or that your water supply inlet is too high.³ Adjust valves accordingly until you get the results you want.

If these solutions don’t work, you might have a problem with your chemical injector. It might be clogged and need to be cleaned. You can test for blockage to identify which parts are causing the problem by removing the high-pressure hose from the pump and starting the engine. If you see siphoning action, add one component back at a time until the siphoning drops off. Clean that component and try again. You may have to clean your entire chemical injector, in which case you should check your manual for instructions. ³

You can also replace components using a chemical injection kit.⁴

Why is my pressure washer pulsating?

Pressure washer pulsations have a couple of potential causes. Sometimes it’s an issue of a filter or a hose that has gotten clogged or pinched, so check those elements for obstructions and issues.

Additionally, similar to the issue of surging, pulsating could be due to a dirty inlet or discharge valve, so try cleaning those parts out and see if that fixes the problem. Generally, you’ll want to do this every 5-6 uses anyways (and every time after pressure washing wood). ⁵

Why is my pressure washer running rough?

If you notice that your pressure washer seems to be running hard, it’s typically an engine problem. Potentially the carburetor isn’t getting the amount of fuel that it needs.

Try checking the carburetor for old fuel buildup. You might need to clean and replace it. Other components you might want to check for clogs and clean/replace include your fuel filter and your gas cap vent. ⁶

It could also be that the water in your pressure washer was too hot. Make sure you use cold water in your pressure washer at all times.

If there’s a possibility that the water in your hose was warmed by the sun before the hose was hooked up to your washer, run water through the hose for a while before attaching your pressure washer. Once everything is connected, keep the water flowing by squeezing the spray trigger at least every 60 seconds so that the cold water can cool your pump.

Final Suggestions for Your Pressure Washer

We hope this guide has helped you to pinpoint and fix the issues you're having with your pressure washer.

Check out our article about troubleshooting your pressure washer’s water pump if you need extra help.

Don't forget: if you want to spend less time troubleshooting and fixing your pressure washer and more time using it, proper maintenance is key. Conducting regular maintenance and replacing inexpensive parts is far more logical (and financially sound) than buying a new unit every few years.

Be sure to check out The ROP Shop’s selection of pressure washer replacement parts and accessories. You can also contact our customer service representatives, and they will be happy to help you find the right part at a great price.

[REVISED 4/2023]