Pressure Washer Troubleshooting (Pro Version!)

By Power Tools

September 12, 2019

Having your pressure washer dead in the middle of a job is irritating.

Pressure washer troubleshooting guide

I know you feel blaming your luck, “I wish I could fix it like a mechanic”. Believe me, it’s really easy.

Give a couple of minutes reading this article and you will learn pressure washer troubleshooting at home.

I am an engineer in the profession which made dealing with these problems easier for me. But you can also master them and get a call from your neighbors to fix their pressure washers.

Before moving on, let me share my own story with you.

When I first bought a pressure washer for washing my car, which was an electric one. And having one year warranty I thought that is going to be awesome.

But, I got into real trouble when the pressure washer stopped working. Back then, I thought I put the wrong pressure washer detergent.

Luckily, I had some experience in my profession and start reading the manual. To me, it worked by changing the water pump oil and purging air from the pump.

No one likes the frustrating failure of a pressure washer. That is why you will love this pressure washer troubleshooting guide.

Fix them by yourself without any previous knowledge.

Pressure Washer Troubleshooting Guide for Most Common Pressure Washer Problems

There are some common problems that occur over time. Used pressure washer (bought used) tends to cause trouble much more than new ones. Cordless pressure washers do not pose difficulties except the battery.

I have years of experience on this equipment and helped a bunch of people with their pressure washer.

From my experience and with the help of the internet I summarized the most common problems. You can find the problem you are facing and fix them in minutes.

Before doing anything read the owner’s manual and safety precautions first for a clear concept of pressure washer basics.

Electric Pressure Washer Problems

Machine Does Not Start:

  1. Faulty Electric Outlet: Need to check the main fuse and plug.
  2. Motor Problem: If under warranty period return it.
  3. If all fails please check the main connection.

Machine Shutdown While Running:

  1. The main issue is the low voltage. Please check the voltage of your connection.

Gas Pressure Washer Problems

Gas power washers produce much power and have a gas-powered engine to deal with.

Engine Stops While Running:

  1. Check Oil Level: Low level of engine oil can cause this problem.
  2. Dusty air filter: Too much clogged dusty air filter need to be cleaned or replaced.

Low Power:

  1. Dusty air filter: Clogged air filter supplies low air resulting in less power.
  2. Faulty fuel injector: Supply of less fuel can cause this issue. Clean or replace the injector.

Oil Leakage:

  1. Oil seals can get damaged or get worn over time. Replacing them is the only solution.

Engine Does Not Start:

  1. First, check if there is gas in the engine or not.
  2. De-pressurize the system by squeezing the trigger
  3. Spark plug malfunction can be a cause. Please check the spark plug connection.
  4. You may even need to replace the spark plug

Problems Related To Water Pressure

Pressure washer problems pulsing:

  1. Most of the time the main cause of this type of problem is a faulty pump which can only be solved by replacing with a new one. The second reason is the pump sucking air. In this case, you need to turn off the machine and release the pressure by continuously pressing the trigger.
  2. In some cases, a clogged nozzle can be the issue. A damaged inlet valve manifold can be a cause too and need to be cleaned.

Low-Pressure Problem:

  1. Most of the time insufficient water supply is the main reason. You need to ensure full water pressure from the water supply.
  2. Need to clean the inlet water filter and ensure proper water supply.
  3. Use proper nozzle

There is No Pressure:

  1. Unloader Valve is damaged: In this case, you need to tighten the unloader screw and check for any damaged seal.
  2. If inlet manifold parts are damaged you need to replace them.
  3. Spike in sudden pressure or pressure drop is related to faulty unloader valve. Please repair or change it.
  4. Use the proper nozzle.
  5. Check your spray gun. If it’s damaged get a pressure washer spray gun replacement from the market. Moreover, check your pressure washer nozzle fittings or couplers are ok.

Pressure Washer Pump Problems

Pressure washer pump is the core life source of a pressure washer. Having it dead is really a serious issue.

However, most of the cases pressure washer pump problems are generated due to bad use practice.

Let me clarify.

The most common cause that can shut the pump off is running the pump without any water supply. This can happen when you are not aware that there is no water coming from the water supply. Running the pump dry damages the pump. In addition, if you forgot to winterize a pressure washer, then this is a common issue.

Ok now let’s jot down the main problems.

  1. No water supply. The pump is accidentally running in dry condition.
  2. Low oil level.
  3. The inlet filter is clogged by dirt or other debris.

Now let’s learn how to deal with them.

Firstly, before doing anything check out the warranty card for a valid warranty period. A warranty will save you some money and time.

Each company provides some good length of the warranty period for specific parts.

Now, for the first problem (running the pump dry) is most common and can cause good damage to the pump. The pump can get burnt. The broken blade is another consequences.

What you can do is always check if the water supply is all ok. Normally the sound will be completely different than a pump running with full water supply. When you notice this mistake turn off the pump immediately and let it cool down before starting it again.

For the second problem, the rotating pump components can get broken due to the low oil level. The pump will get extremely hot without oil.

Check the oil level regularly to avoid this kind of troubleshooting.

Finally, check the inlet filter screen for debris. This kind of debris blocks the filter (inlet) and puts pressure on the pump.

This will definitely put extreme pressure on the pump and damage it.

Clean the screen for proper suction by the pump.

Essential Tools Required

Definitely, you can’t just troubleshoot with bare hands. You need some tools and accessories.

But first, let me show you my own toolset.

pressure washer troubleshooting tools

Yeah! That is some pro toolset. Tools industry is really filled with amazing items.

I do not carry it everywhere but own it. As an engineer in a profession, this kind of toolset is inspirational.

But you do not need this kind of mega toolset. Just some tools to get you through the troubleshooting process. But you can disassemble a pressure washer.

Here’s the shortlist:

  1. Allen Keys (Hex Keys)
  2. Socket screws
  3. Wrenches
  4. Cordless ratchets
  5. Hammer
  6. Knife
  7. Pliers
  8. Screwdrivers