Pressure Washer Turns Off When The Trigger Is Pulled? 5 Surprising Causes!

Are you wondering why your pressure washer turns off when the trigger is pulled? There can be multiple reasons. Read this article to find out the causes and tips to fix the issue.  

A pressure washer is an essential appliance for cleaning large areas and surfaces. It is used for both domestic and industrial cleaning purposes. The pressure washer creates a high-water pressure stream, which helps in cleaning. It also assists in removing stubborn stains.   

pressure washer turns off when the trigger is pulled

It is used for cleaning multiple areas and surfaces. You can use a pressure washer to clean the exterior of your house, patio, driveway, sidewalk, garage, roof, and as well as windows and panels. Additionally, the pressure washer is utilized for washing cars, boats, and trucks. The high-pressure gun is one of the essential components of the pressure washer. When the high-pressure gun trigger is released, it sprays the stream of water. You can point this stream towards the surface that is to be cleaned. The most common problem with a pressure washer is it turns off when the trigger is pulled. 


Causes Why Pressure Washer Turns Off When Trigger Is Pulled

These can be the causes of why your pressure washer turns off when the trigger is pulled:


Cause #1. Failure of the unloader valve 

The most common cause of pressure washer not operating is the unloader valve. The fault in the unloader valve prevents the pressure washer from turning on when the trigger is pulled. The unloader valve regulates the water pressure and enables a high-pressure water stream to flow from the nozzle. When the trigger is released unloader valve redirects the water flow in circles to maintain high pressure. If the pressure in the pump surpasses the pressure in the engine, the engine will halt.  

The typical issues with the unloader valve include damaged O rings, build-up dust, and debris in the spring or blocked shafts. You will require a screwdriver and a wrench to disconnect the unloader valve. The unloader valve is kept in place by a retaining pin. Therefore, you will have to unscrew the retaining pin to disconnect the unloader valve.  

Once you have successfully disconnected the unloader valve, pull out the piston and examine it. The piston is the essential part of the unloader valve. The piston should be able to move freely when the trigger is pulled. It moves back and forth to maintain the water pressure. When the motion function of the piston breaks off, it causes the pressure washer to stall. Therefore, you will have to inspect it for clog and damage. The screw which holds the piston can be removed using a screwdriver. Use kerosene to clean the piston and then grease it before attaching it back.   

Check the pressure setting of the unloader valve. When the position of the unloader valve is, high the pressure washer will turn off when the trigger is released. You will have to adjust the valve to maintain the water pressure. Finally, examine O rings; if they are damaged, you will have to replace them. The damaged O rings cause leaking from the fuel pump; as a result pressure washer turns off when your trigger is pulled. 

You may also want to read about how to adjust unloader valve on pressure washer.


Cause #2. Dirty air filter  

The dirty air filter prevents the pressure washer from working. Before you clean or replace the carburetor, check the air filter. A dirty air filter can clog the pressure washer carburetor. The air filter is present on the exterior of the pressure washer beside the fuel pump. Using a screwdriver, pull out the air filter. Clean the air filter with soap water so that all the dust and debris are eliminated. If the air filter is damaged, you will have to replace it.   


Cause #3. Clogged or loose carburetor

The clogged or loose carburetor can also cause the pressure washer to stall when the trigger is pulled. The carburetor is a vital component of a pressure washer. It is required for the combustion of fuel. To clean the carburetor, you will have to eliminate the residual fuel from the pressure washer. Using a screwdriver, disconnect the carburetor. The jet is the prime location for clog formation.  

There is a tiny hole for the passage of air in the carburetor; remove the clog from that hole using a thin metal wire. Next, spray the carburetor cleaner all over the carburetor and wait for a few minutes. Then rinse it with soap and water. If the carburetor has rust or is damaged, you will have to replace it. Know how to unclog a pressure washer.


Cause #4. Faulty pressure gun  

After cleaning or replacing the unloader valve, air filter, and carburetor, if the problem is still not resolved, investigate the pressure gun. The pressure gun allows a limited quantity of the water to flow or spray out of the pressure washer. The main function of the pressure washer gun is to prevent the water in the pressure washer from freezing. The clogged or damaged high-pressure gun turns off the pressure washer whenever the trigger is pulled. 


Cause #5. Faulty spark plug  

The spark plug is essential for operating the pressure washer. A dirty or damaged spark plug will prevent the pressure washer from working. Unscrew the spark plug and clean it. If it is damaged, replace it. Here’s how to check a spark plug.


It’s A Wrap! 

By checking all the components of the pressure washer mentioned above: you can figure out the reason why the pressure washer turns off when the trigger is pulled. The pressure washer can be repaired without any help. Most of the time, it only requires good cleaning of the parts. Replace the damaged or rusted components.

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