Pressure Washer Shuts Off When Trigger Is Pulled – How to Fix


Pressure Washer Shuts Off When Trigger Is Pulled

As an affiliate, we may earn a commission from qualifying purchases. We get commissions for purchases made through links on this website from Amazon and other third parties.

Not many home cleaning machines come close to the pressure washer in cleaning efficiency and speed. Thus, it won’t come as a surprise to anyone that the pressure washer is ever-present in most homes. However, what happens whenever the pressure washer shuts off when trigger is pulled? Does it point to other underlying issues that might spell trouble for your washer?

If you own a pressure washer, this might be one of the issues you have faced or will face. So how do you solve this issue? You start by reading this write-up to the end.

Why Your Pressure Washer Shuts off When Trigger is Pulled/Released?

For many pressure washer owners, a puzzle is known when the pressure washer shuts off when the trigger is released. It is vital to appreciate the need for having all the facts before attempting to troubleshoot this problem.

Last update on 2024-03-16 / Affiliate links / Images from Amazon Product Advertising API

What exactly goes wrong before a pressure washer behaves in that manner? Several reasons would cause your pressure washer to shut off whenever you pull the trigger.

Issues to do with the pressure washer shutting whenever you pull the trigger usually stem from a problematic unloader valve. The unloader valve is responsible for cycling water back to the inlet by opening itself up.

Therefore, if the setting for your unloader valve is high, it might keep stacking the pressure washer engine whenever you release the trigger.

Therefore, whenever the unloader valve fails to open, there is a buildup of pressure inside the washer, causing the stalling of the engine.

Have you given thought to the pressure washer unloader valve’s O-rings? If these rings are in bad shape, they might fail in their duty to seal the oil pump. As a result, the unloader valve might also fail to work, leading to the engine’s shutting. Check O-Ring on Amazon

A problematic pressure gun might also cause the pressure washer to stall when you pull the trigger. That is especially so if it is in bad condition.

Pressure Washer Dies When Trigger Is Pulled: What to do

Pressure Washer Dies When Trigger Is Pulled

You need to follow several steps to fix the problem.

Step 1

Using a screwdriver and a wrench, unplug the unloader valve. You will do this by first removing the retaining pin, which keeps the unloader valve in place. This should be complicated since the unloader valve is easily visible.

To unscrew the pin, you enter the screwdriver inside the pin and pull it upwards to remove it. Thus, the unloader valve will be easier to remove since you have already removed the pin that holds it in position.

Step 2

After removing the unloader valve, remove the piston and inspect it. There is a nut that holds the piston onto the valve. The screwdriver should help you easily remove it. The piston controls the valve’s pressure retention capabilities.

The piston should move freely every time you turn on the pressure washer. If it doesn’t, then the pressure washer’s engine stalls.

Step 3

After removing the piston from the valve, use either kerosene or alcohol to clean it and eliminate any dirt. After that, grease it with silicone grease and set it back into the unloader valve.

That will allow it to resume normal functioning, which is moving freely. However, if you have noticed that the piston was moving freely, then there wouldn’t be any need for this step.

Step 4

Check the unloader valve’s pressure setting to ensure it is in the right setting. If the setting is too high, then the engine will have issues continuing operation when you release the trigger.

If the seating is too high, then the unloader valve won’t enable the water to cycle back into the inlet to release the pressure. The buildup of pressure will cause the pressure washer to stall.

If the setting is too high, adjusting t to the required level will help stop the pressure washer from stalling when you push the trigger.

Step 5

Check the unloader valve’s O-rings. If they are in good condition, then move on to the next step. If, however, they are in bad shape, replace them with new ones. Ensure the new rings are the same size as the previous ones.

Captain O-Ring – Power Pressure Washer O-Rings for 1/4″ Quick Coupler, High Temperature Viton FKM (10 Pack)
  • Viton FKM Rubber is compatible with many chemicals and cleaners
  • O-Rings measure 3/8″ Inside Diameter x 0.100″ Thick. These 3/8″…
  • Compatible with temperatures up to 400F

Last update on 2024-03-16 / Affiliate links / Images from Amazon Product Advertising API

Deteriorated O-rings cannot seal the oil pump well enough, which may cause the unloader to malfunction and stall the pressure washer.

Step 6

If all the steps we have discussed, don’t help:

  • Check the pressure gun for any issues. If it isn’t in a good state, then replace it.
  • Check for any issues in the air filter and clean it
  • Use alcohol to clean the spark plug
  • Check the wand screens

Last update on 2024-03-16 / Affiliate links / Images from Amazon Product Advertising API

If all the above fails, you can decide to take it to a pressure washer expert to see whether they can repair it. If not, you can choose to buy either a new unloader valve or a new pressure washer.

Read Also: How to Clean Pool Tile with Pressure Washer

Important Points to Remember

  • If you decide to get a new unloader valve, ensure you buy from certified dealers to avoid getting an artificial valve. If possible, you can purchase one from Amazon to be assured that it is genuine.
  • Remember to do the regular maintenance of your pressure washer to prevent issues. It is advisable to clean out the inner parts from time to time.
  • Before deciding to seek a repair, experts help ensure the expert is well versed in handling such devices. You don’t want someone to damage a functioning washer in the name of repair.

FAQs About Pressure Washer Problems

Why Your Pressure Washer Shuts off When Trigger is Pulled

How do you know if your unloader valve is bad?

The effects of a faulty unloader valve can be noticed by the throttle response. If there is an open/close fault in the unloader valve, then the throttle response will be delayed, backfiring, or stalling. The engine may also show irregular idle speed and have low power output which is often reflected on the engine RPM needle. It can be difficult to diagnose faults in engines without specialized equipment, but some faults are easier to identify than others.

Why does the pressure washer keep stalling?

A pressure washer may stall for a variety of reasons; however, the most common cause is a dirty fuel filter. The engine will not run properly if there is dirt and debris in the fuel system that clogs the carburetor and makes it difficult for any gas to enter the engine. A dirty or worn spark plug may also be the reason your pressure washer is stalling.

Can you adjust an unloader valve?

The unloader valve of a pressure washer is the release valve on the tank which allows for the water to be released in small quantities when it is not being used. The valves are often labeled with words like “high” and “low” to help identify what they do.

An unloader valve can be adjusted by turning the knob clockwise will cause water to flow out of the valve more quickly, or counter-clockwise will result in slower flow.

Why does my pressure washer idle up and down?

There could be a problem with the pressure washer’s engine, there may be dirt in the nozzle, or there might be an issue with the hose. Some of these problems can cause other issues if they are not tackled properly. If the engine is running too lean, this can cause other problems like fuel starvation or detonation.

How do I know if my pressure washer wand is bad?

A pressure washer wand is a hose that directs water from the power washer’s pump to the cleaning surface. The tip of the wand can be fitted with an accessory head for different tasks. To diagnose whether your pressure washer wand is bad, you should observe how it sprays and test its spray pattern. A good pressure washer usually produces a fan-shaped spray pattern as opposed to a circular one.

Why does the pressure washer only run with the choke on?

The reason your pressure washer only runs with the ‘choke’ on is that it is not receiving enough fuel. The engine is not getting enough air and fuel to fire and run so the choke will be on for a little while to give the engine some extra breathers of oxygen. The choke prevents cold water from entering the engine and seizing it, so if you stop using the choke, water will seep into the engine and cause it to stall.

Final Thoughts

We hope our guide helps you solve your issue when your pressure washer shuts off when trigger is pulled. Follow all the guidelines we have laid down for you. It will be easier to diagnose the problem and find a suitable solution.

Remember to keep the pressure washer in good working condition to prevent any issue with the engine suddenly being faulty.

Relevant Resources:

  1. Top 5 Best Mrliance Pressure Washer Reviews
  2. Top 5 Best Gas Pressure Washer Under 300
  3. 5 Best Commercial Hot Water Pressure Washer
  4. 10 Best Pressure Washer Soap, Detergents, & Chemicals
  5. Top 7 Best Pressure Washer Surface Cleaner Reviews
  6. Top 7 Best Pressure Washer Sandblasting Kit
  7. Top 9 Best Car High Pressure Cleaning Tool Reviews

Latest Posts

  • How to Remove Eggshell Paint from Clothes

    How to Remove Eggshell Paint from Clothes

    Are you tired of staring at that unsightly eggshell paint stain on your favorite shirt? Don’t worry! In this comprehensive guide, we’ll walk you through effective methods to remove eggshell paint from clothes. With a little know-how and some common household items, you’ll be able to say goodbye to those stubborn stains and restore your…

    Read more

  • How to Remove Solvent Cement from Clothes: A Comprehensive Guide

    How to Remove Solvent Cement from Clothes: A Comprehensive Guide

    This comprehensive guide covers 5 effective methods on how to remove solvent cement stains from clothes. Learn how to safely treat stains on various fabrics.

    Read more

  • How to Remove Fiberglass from Clothes: A Complete Guide

    How to Remove Fiberglass from Clothes: A Complete Guide

    Have you ever found yourself in a situation where you accidentally brushed against a fiberglass surface, only to discover later that your clothes were covered in those pesky fibers? Fiberglass can be quite stubborn and cling to fabrics, making it challenging to remove. STAR BRITE Ultimate Fiberglass Stain Remover 16 OZ – Easy-to-Use Marine Grade…

    Read more