pressure washer shuts off when trigger is pulled

Pressure Washer Shuts off When the Trigger Is Pulled? Here’s How to Fix It!

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If you are reading this, it is likely that your pressure washer shuts off when the trigger is pulled. It’s a common issue homeowners encounter when cleaning exterior surfaces.

The wonderful news is that you can take steps to fix this problem! With just a few minutes of troubleshooting, your pressure washer be back up and running!

Reasons Why Your Pressure Washer Shuts off During Use

If your pressure washer dies when the trigger is pulled, it could be due to the following reasons:

Faulty Unloader Valve

The unloader valve is one of the essential components of your pressure washer. If the unloader valve is defective, it can cause your device to shut off without warning.

Unloader valves are an automatic safety mechanism. They release any excess water in your pump when it gets too hot or sudden temperature changes.

The unloader valve also protects you from being blasted by extremely high-pressurized water when you release the trigger on your hose spray wand.

The unloader valve is usually situated on the front of your pump. If you’re having trouble with yours, consider replacing it to see if this solves your problem.

Clogged Filter

Another possibility is that the filter on your pressure washer is clogged. This can be caused by various things, such as dirt, debris, or even insects. If the water inlet filter is clogged, it will prevent the machine from functioning correctly and could cause it to shut off.

Damaged Spark Plug

A faulty spark plug can also be responsible for your pressure washer shutting off. If this is the case, you will have to replace it.

Ignition Coil Issues

Another cause of pressure washer shut-offs could be an issue with the ignition module or coil. If there’s a problem here, it won’t allow the starting sequence for the engine to run correctly.

Low Fuel

One of the most common reasons your pressure washer will turn off is because there’s not enough fuel in the tank. If this is the case, adding more fuel may be all you need to do to get your machine running again.

Damaged Switch

If your pressure washer bogs down when you pull the trigger, this may be an indication that there’s a problem with the switch. The gun or wand assembly might need to be replaced if it is faulty.

Spark Arrestor

If you use your pressure washer on a property with grass, small rocks or dirt may get pulled up by your device and enter through the spark arrestor. This could cause damage to the engine of your machine.

Insufficient Oil

If your pressure washer is shutting off because of low oil levels, adding more may not be the solution. In this case, you will need to take the machine to a professional to have it serviced.

Pump Issue

A faulty pressure washer pump could also be the culprit for why your pressure washer shuts off. In this case, the pump system needs to be replaced with a new one.

Defective Engine

Another possibility for why your machine stalls during use could be due to an issue with the engine itself! In some cases, a professional may need to service or replace their engine for the machine to function again.

You can quickly determine why it shuts off during use by troubleshooting your cleaning tool. Once the issue is identified, a solution will be much easier to find!

Defective Water Inlet

man using power washing tool

Another possible reason your pressure washer shuts off when you pull the trigger could be a faulty inlet water valve. Your inlet water valve is responsible for regulating the flow of water coming into your power washer from the water supply.

If this inlet is defective, it can cause the pressure washer to turn off suddenly or not produce any water at all. This can be a genuine inconvenience if you’re in the middle of cleaning your driveway and have to stop to fix the problem.

Pressure Washer Shuts Off When the Trigger Is Pulled: Quick and Easy Fixes

Here’s how you fix a pressure washer that shuts off when the trigger is pulled. Follow the easy steps below.

Step 1: Prepare all the tools and materials Needed

You will need the following when troubleshooting your pressure washer:

  • Screwdrivers
  • Wrench
  • Alcohol
  • Pliers
  • Clean rags
  • Grease

Step 1: Detach the Unloader Valve

Unloader valves are designed to keep the pump in pressure washers from working too hard. It controls pressure retention within the pump such that it doesn’t go higher than that of the engine.

Most pressure washer problems start and end with a problematic unloader valve. The pressure increases when the unloading valve is caked with dirt or has damaged parts. Hence, your pressure washer won’t stay running if you have a faulty unloader valve.

To check the unloader valve, you need to detach it from the bay using a screwdriver and a wrench. Loosen the retaining pin that fastens the unloader valve. Then, position the screwdriver inside the valve retaining pin and gently pull it upwards. You need to do this step carefully to prevent damage.

Step 2: Remove and Inspect the Piston

The piston can also be why your pressure washer dies when the trigger is pulled. The piston should be moving freely. The pump may overheat if it doesn’t because it is dirty or damaged.

Use your wrench to remove the piston from the unloader valve. Push down on the spring and pull out the piston. Inspect both for damage and remove stubborn dirt with alcohol if it works fine. Dry the spring and piston and apply some silicone grease before putting them back into place.

However, if the piston is damaged, you need to replace it with a new one.

Step 3: Adjust the Unloader Valve Settings

Inadequate pressure regulation or excessively high pressure can be the reason why your pressure washer keeps shutting off. You need to adjust the unloader valve’s settings to avoid pressure build-up to fix this problem.

The engine needs to be running when you adjust the unloader valve’s pressure settings to an optimal level. To do this, turn on the valve to let all the air out of the pressure washer.

Then, regulate pressure by tightening the spring in the unloader valve controls. The lock nuts should be moved while you adjust. After adjusting the unloader valve setting, release the pressure washer trigger and replace the lock nut and spring.

Step 4: Inspect the O-Rings and Oil Pump

An o-ring is essential for the proper sealing of the oil pump. Damaged o-rings are sometimes the cause why your pressure washer stalls under load. When an o-ring gets worn out, it fails to seal the pressure washer’s oil pump. A faulty o-ring could lead to unloader pump malfunction, too.

If there is a tear or damage to the o-ring, you need to replace it immediately. Ensure that the new o-ring is in the correct size. Also, check that the replacement o-ring can seal the oil pump completely.

Step 5: Inspect the Trigger

If the trigger of the cleaning tool is faulty, it could lead to random shut-offs. If you find something wrong with it, replace it immediately.

Step 6: Check for Other Issues

If you’re done with steps 1 to 5, but the pressure washer still bogs down when the trigger is pulled, do the following:

  • Inspect the pressure gun if it’s working correctly. Replace as necessary.
  • Clean the spark plug with alcohol.
  • Inspect the wand screens.
  • Inspect the air filter if it’s dirty. You can easily clean a dirty air filter with alcohol.

If the pressure washer is still shutting off when you pull the trigger and all of the previous steps have been followed, there may be an issue with the engine itself. In this case, take your pressure washer to a professional for repairs. You may also need a new unloader valve in this case.

Essential Pressure Washer Maintenance Tips

trigger of power washing tool

Here are some tips for maintaining your new pressure washer:

  • Avoid leaving the trigger pulled for long periods when not in use. Doing this could damage the unloader valve. Keeping a pressure washer idle for more than a few minutes can overheat the pump and engine.
  • Avoid overloading the pressure washer with water or cleaning solution into it. Doing this could cause damage to the internal components of the machine, too.
  • Use cleaning solutions formulated specifically for your power washer.
  • If you have a gas engine-powered model, change your fuel filter regularly for clean burning and best performance results.
  • Do not run out of gasoline during operation, which could lead to the engine’s failure. Ensure there’s enough fresh fuel in the gas tank.
  • Store the pressure washer in a dry place. If you have to store it outside, make sure it is covered and elevated off the ground.
  • Regularly check all fasteners and screws on the pressure washer for tightness. This will help avoid any leaks from occurring.
  • Clean the pressure washer regularly. Don’t forget to remove and clean the inlet filter with running water. Clean out any stubborn dirt and debris with a soft toothbrush.

Safety Considerations When Using Pressure Washers

Here are some safety tips to remember when using a pressure washer:

  • Wear goggles and gloves when operating the machine.
  • Make sure that bystanders and pets are kept at a safe distance from the area you’re working in.
  • Never point the spray wand of the pressure washer towards anyone, especially if it’s loaded with cleaning solution. This can lead to high-pressure water injection injury.
  • Keep the engine away from water as it may cause a short circuit and lead to serious injury.
  • Always turn off the pressure washer before changing detergent tanks or disassembling any of its parts for maintenance purposes. Also, let all the air out of the hose before you store it to prevent damage caused by excess pressure.
  • Prevent trips and falls by using caution when walking around the area you’re working in.
  • Be aware of your surroundings and what’s going on in them at all times. This will help avoid any unexpected accidents from happening.

Frequently Asked Questions About Pressure Washer Maintenance

What to Do if Your Unloader Valve Fails?

If your unloader valve fails, you may need to replace it with a new one or call a professional for repairs.

Where Can I Find a Replacement Unloader Valve?

You can purchase a new unloader valve at most online stores or local retailers that carry parts for power washers.

What’s the Best Pressure Washer Model Available?

The best pressure washer model available is the one that meets your specific needs. Some models include gas-powered and electric units with various features to choose from.

Can a Pressure Washer Malfunction Due to Low Psi?

In some cases, shutting off under load could be due to low psi from the pressure washer. In this case, you need a boost of power by increasing the pump’s speed or cleaning rate if possible. 

You can also increase water flow into the power washer to address the low pressure. If these methods do not work, it’s time to call a professional.

Where Can I Find a Pressure Washer Unloader Valve Diagram?

You can find a pressure washer unloader valve diagram on the manufacturer’s website.

Can I Use an Extension Cord With My Pressure Washer?

If you have to use an extension cord, make sure that it is rated for outdoor use and the proper amperage for your machine.

How Much Does a Pressure Washer Cost?

Prices for pressure washers vary depending on the model and features you choose. You can find a wide range of prices, from budget-friendly to high-end models.

Cleaning Outdoor Surfaces With Ease

Now that you know what to do when your pressure washer shuts off when the trigger is pulled, outdoor cleaning will be so much easier.

For clarifications on fixing issues with your pressure washer, let us know in the comments. For suggestions on topics to cover for our future articles, leave us feedback. We’re excited to hear from you!

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