Pressure Washer Turns Off When Trigger Is Pulled

Pressure washers are common equipment in many homesteads. Their popularity is as a result of their efficiency in cleaning stubborn surfaces on the vehicle and other surfaces inside and outside your compound. A pressure washer will perform all those duties when in good conditions but what will you do when the pressure washer turns off when trigger is pulled?

A pressure washer can turn off when trigger is pulled mainly because the loader valve has broken-down, a problem with the piston, or worn out O-rings. It can also be caused by problems with the pressure washer trigger and poor adjusting of the unloader valve or an issue with the carburetor.

As a pressure washer owner, it is important understand what can lead it stalling and how to solve it.

Below is a guide to help you understand the problems and how to fix them.

Things to consider before fixing a Pressure Washer that is turning off When Trigger Is Pulled

Before you try fixing a stalled engine, first understand what type pressure washer you have. There are four types of pressure washers.

  1. Hot water pressure for cleaning grease and oils.
  2. Cold water mostly used by homeowners.
  3. Gas powered cold water pressure best for outdoor cleaning.
  4. Electric powered cold water pressure best for cleaning surfaces that are easily damaged.

Remember that there are different ways of powering an engine, it can be powered by electricity, diesel, or hydraulic pressure. These are important considerations when deciding how to fix a pressure washer.

6 Reasons why Pressure Washer Turns Off When Trigger Is Pulled and What to Do

 Faulty Unloader Valve

Mostly pressure washer shuts off when the trigger is pulled because of an issue with the loader valve. This will lead to the pressure building up in the machine when the trigger is released. The result will be the pressure washer turning off when the unloader valve fails to work.

You should dismantle the unloader valve to check if there is dirt, worn out O-rings, or a stuck shaft.

 Use a wrench and a screwdriver, take out the unloader valve. Use minimum force when removing it.

Problem with the piston

This is the main part of the unloader valve that helps in retaining pressure. It does this by moving back and forward when the pressure washer being used.

When the piston is not in good condition, the pressure washer will shut off. This can solved by replacing the piston.

 Cracked O-rings

The O-rings cover the oil pump and prevents leakage. Unluckily, the O-rings needs to be replaced regularly as they wear out easily. When the O-rings crack they cannot cover the oil pump as required, this will make the unloader valve to malfunction.

The O-rings should be replaced using grease and thread tape to fix it properly.

Poor Settings with the Unloader Valve

If the piston is not working, the problem might just be with the unloader valve settings. If it is put on a very high setting, it will not work properly.

The high settings will make the pressure to build up inside and make the washer to turn off when the trigger is pulled.

You should adjust the setting so that the unloader valve can open and release water to prevent pressure build up.

Set your washer to produce the desired pressure depending on what you want to wash. Some objects and surfaces requires more pressure than others.

 Problems with pressure washer trigger

If you have checked all the above parts of your pressure washer and it is yet to function, you should inspect the pressure washer trigger.

Use a replacement to see if will function properly.

6. A problem with the Carburetor

An issue with the carburetor can make the pressure washer turn off when trigger is pulled. The carburetor can either be loose or clogged. The loose carburetor should be tightened and the clogged one requires cleaning by draining of the gas tank.

Other potential solutions to fix your pressure washer dying when the trigger is pulled

The hacks below might help your pressure washer if the above solution didn’t work;

  1. Confirm that the wand screens are ok.
  2. Top-up the oil levels if low.
  3. Ensure there is adequate flow of water to the washer pressure.
  4. Release air pressure from the washer.
  5. Inspect the spark plugs and cleanse with alcohol if you are using gas pressure washer.

What are some common causes for a pressure washer staying on after being turned off?

This problem can be caused by to things; problem with the unloader valve or the nozzle was not closed and it continues to spray water.

It can also be as a result of a stuck trigger.

Tips to Remember

  1. Buy your unloader valve from a certified dealer to be sure its original.
  2. Regularly service your pressure washer to avoid inconveniences of breaking down when work is in progress.
  3. If you don’t know how to handle a repair problem, call a professional to avoid making more mess.

What are some different types of pressure washer unloader valves?

There are two  categories of pressure washer; unloader valve manual and automatic. Manual has to be pushed down to open while the automatic has an automated spring that helps in pushing down.

What’s the difference between an automatic unloader valve and a manual one?

What differentiates the two unloader valves is that the automated one water will come out when the trigger is not on or off properly but for the manual one, the water will stop coming out immediately after you release the trigger.

How do you know if your unloader valve is bad?

The obvious sign that your unloader is bad is decrease in the amount of water coming out of the nozzle. A bad unloader valve will lead to a decrease in water pressure.


A pressure washer can turn off when trigger is pulled because of many reasons. I hope this article will help you identify the problem with your pressure washer and make fixing it easier.

Remember to buy original pressure washer and service it regularly.

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