Pressure Washer Dies When I Pull the Trigger: Helpful Tips

A pressure washer is a valuable piece of equipment that helps remove stubborn dirt and on many surfaces outside the house or on your car. Cleaning dirty surfaces effectively with a pressure washer is a satisfying job until the pressure washer stops working. One of the more common problems is that the pressure washer stalls when the trigger is pulled.

Pressure Washer Dies When I Pull the Trigger:

In general, a pressure washer shutting off when the trigger is pulled indicates a faulty unloader valve. An unloader valve is one of the most critical parts of the pressure washer. Hindrances in the piston movement, deteriorated O-rings, loose spring, inappropriate setting of the unloader valve, and faulty pressure washer trigger can cause the pressure washer to shut off when it is pulled.

This article will provide you with information about the different causes of the pressure washer stalling when the trigger is pulled or released. I will also show how to diagnose and repair the unloader valve.

Why Does My Pressure Washer Die When I Pull the Trigger?

A pressure washer stalling when the trigger is pulled is mostly due to a faulty unloader valve, O-rings, pressure washer trigger, or a too-high setting of the unloader valve.

The root cause of a stalling issue is usually a problematic unloader valve. The unloader valve cycles the water back to the inlet, diverting the flowing through the pump system. The unloader valve redirects the water into a loop when the trigger is released. This helps to retain the water pressure even when it’s discharged through the nozzle.

Here are some common problems that cause the pressure washer to stall when the trigger is pulled.

● Faulty unloader valve:

Most pressure washer problems start and end with the unloader valve. The unloader valve controls the pressure and allows the water to come out of the nozzle with high strength. It diverts the flow of water into a loop to retain high pressure when the trigger is released. When the pressure in the pump exceeds the engine pressure, the engine shuts off. The most common problems in the unloader valve are cracked O-rings, accumulated dirt in the spring, or a stuck shaft.

● Problem with the piston:

The piston controls pressure retention and is one of the most important parts of the unloader valve. The piston moves back and forth when the pressure washer is operating. When this back and forth movement is stopped or interrupted, the pressure washer shuts off. To inspect the piston, remove it from the unloader valve.

● Worn out O-rings:

Faulty and deteriorated O-rings cause leakage from the oil pump, which doesn’t allow the unloader valve to work correctly. As a result, the pressure washer shuts off when the trigger is pulled. You must check the O-rings of the unloader valve and replace them if they are cracked.

●Poor pressure setting of the unloader valve:

High-pressure settings inhibit the engine’s ability when the trigger is released. This is because, at higher settings, the unloader valve doesn’t allow the water to divert in the loop to the inlet to release pressure. This builds up the pressure in the machine and causes the pressure washer to stall. You must adjust the settings so that the unloader valve can divert the water back to the inlet to avoid pressure build-up that causes the pressure washer to shut off.

● Problem with the pressure washer trigger:

Fixing all the problems discussed above may not fix the pressure washer die when the trigger is pulled. The trigger may have an issue. First, try another trigger to see if this is indeed the problem. If so, disassemble the trigger and see if you can find a problem with it. Replace it if you can not fix it.

How to Fix A Pressure Washer That Shuts Off When the Trigger is Pulled

To fix a pressure washer shut-off problem, you need to follow some simple steps. Disassemble the unloader valve. Carefully inspect the piston, O-rings, and spring. Adjust the pressure settings of the unloader valve. If the issue isn’t resolved after following all these steps, you must always check the correct working of the pressure washer trigger.

As discussed in the previous section, a faulty unloader valve usually causes a pressure washer to shut off when the trigger is pulled. The unloader valve diverts the water back to the inlet to retain the pressure. When the unloader valve doesn’t work correctly, it stacks the pressure inside the machine when the trigger is released. Pressure builds up inside the pressure washer and causes it to shut off when the unloader valve fails to open.

Here are the steps that will help you to fix the problem:

● Step 1: Inspect the unloader valve

The first step is to inspect the unloader valve. A pressure washer shuts off when the pressure inside the pump increases higher than the engine pressure. Inspect the unloader valve to check for the dirt around the spring, stuck shaft, or worn-out O-rings. You need to disassemble the unloader valve for a thorough inspection.

● Step 2: Remove the unloader valve

You need a wrench and a screwdriver to remove the unloader valve. Remove the retaining pin that keeps the unloader valve in place. Release the pin by unscrewing it and placing the screwdriver inside the pin, and pulling it upwards to remove it. This allows you to remove the unloader valve easily. Don’t use excessive force when removing the unloader valve to avoid damage.

● Step 3: Check the unloader valve

Check the different parts of the unloader valve, such as the piston, O-rings, and the spring, to ensure they are in good working condition.

●Step 4: Inspect the piston

The piston is a vital part of the unloader valve. If the movement of the piston stops or is interrupted, the washer may shut off when the trigger is pulled. If the piston isn’t in good working condition, replace it.

● Step 5: Check the O-rings

O-rings seal the oil pump and ensure that there is no leakage. Unfortunately, these rings get worn out over time. Cracked O-rings can’t seal the oil pump properly, which hinders the working of the unloader valve. To avoid leakage, you must replace the cracked O-rings. You can use grease and thread tape to install the new O-rings properly.

● Step 6: Adjust the unloader valve settings

The unloader valve doesn’t properly divert the water back to the inlet to release pressure at very high settings. This builds up pressure inside the machine, which causes the washer to shut off when the trigger is pulled. You must adjust the settings so that the unloader valve can open and divert the water in the loop back to the inlet to release pressure.

Make sure that the engine is running before you adjust the unloader valve’s settings. To release the air out of the washer, turn on the outlet valve. Tighten the unloader valve spring to achieve the desired pressure. Next, move the lock nuts while adjusting the pressure. Once the desired pressure is adjusted, release the trigger and place the lock nuts, spring and washer back in position.

● Step 7: Inspect the pressure washer trigger

A pressure washer trigger requires regular servicing to work effectively. Remember that fixing all the problems discussed above may not help you to fully solve the problem if your pressure washer trigger isn’t working properly. So, it’s recommended to check and service it. If you are unsure if it works correctly, try to use a replacement and see if that fixes the problem. Replace when needed.

● Step 8: Other potential solutions to fix your pressure washer dying when the trigger is pulled

If all the fixes discussed above doesn’t solve your problem, you may want to try the following:

• Check the wand screens.
• Try to release the air or pressure from the washer.
• Gas pressure washer: Check the spark plugs and clean them with alcohol.
• To regulate pressure, clean the air filter and remove any dirt clogged in it.
• Ensure that the water supply is providing enough water flow into the pump.
• Check the oil level and refill the oil if it’s low.

Pressure Washer Stalls When the Trigger is Released: How to Solve It

A pressure washer stalling when the trigger is released indicates a fault in the unloader valve. To fix the problem, remove the unloader valve from the pressure washer and inspect its various parts. Including the piston, O-rings, and springs. Also, check the valve’s settings and adjust it to the correct value. 

The unloader valve is the (mostly) black handle located at the top of the pump system. When the trigger is released, the unloader valve redirects the water in a loop to retain the pressure. If the unloader valve doesn’t work correctly, the pressure washer stalls when releasing the trigger due to pressure build-up.

To solve this stall, you need to remove the unloader valve and inspect its various parts. Mostly the problem lies in the piston, O-rings, or the spring of the unloader valve. In addition, the pressure washer can also stall when releasing the trigger when the unloader valve is set to a very high setting. 

You only need some simple tools, like a screwdriver and a wrench, to remove the unloader valve. Have some alcohol at hand cleaning the various parts. Use grease while placing the parts back in place.

How to Fix the Pressure Washer Stalling When the Trigger is Released

– Step 1. Remove the unloader valve:

The first step is to locate the unloader valve and remove it. The unloader valve is located above the pump and can be easily identified by the black handle. Unplug it using a screwdriver. Look for the U-shaped retaining pin that holds the valve in position. Remove the retaining pin and use the screwdriver as a lever to pull off the unloader valve.

– Step 2. Check the piston

To ensure the free movement of the piston, unscrew the nut that holds the piston. Disengage the spring and piston from the valve. Clean the piston and spring with alcohol to remove any dirt. Grease the piston and the spring and put them back in place.

The piston plays an important role in the unloader valve’s functioning. When the movement of the piston is restricted or stopped, the unloader valve doesn’t function properly, and the pressure washer stalls.

– Step 3. Check the valve’s settings

The unloader valve regulates the pressure in the pressure washer. The pressure is adjusted and controlled manually. If the unloader valve is set to a really high setting, it can build up very high pressure in the pump that cannot be released easily. This causes the engine to stall when the trigger is released.

To solve this problem, ensure that the engine is running correctly. Locate the pressure adjusting knob on the valve. Adjust the knob slowly to achieve the appropriate settings while holding the trigger. It would be best if you observed a maximum spike between 5% and 10%. If higher, adjust the knob further.

– Step 4: Check O-rings

O-rings deteriorate over time and cause leakage in the oil pump. This may stall the pressure washer. To solve this problem, remove the old O-rings and replace them. 

– Step 5: Place the unloader valve back

Once you have completed the previous steps, reinsert the valve and place the retaining pin to keep the valve in its place. Turn the pressure washer on and check its performance. Hopefully, after following all the steps, the pressure washer stalling problem is solved.

Inspection and Repair of Garden Hose or High-Pressure Hose

Upon finding any signs of leakage in your garden hose or high-pressure hose, it necessitates either a repair or replacement. Leaks could cause a significant drop in the pressure and may even damage the equipment over time.

Based on my experience, I recommend performing regular inspections of the hose, as it helps maintain the overall performance and longevity of your pressure washer.

• Checking for Kinks in the Hose

Often, obstruction in water flow can be due to kinks in the hose. It’s essential to make sure the hose is straight and free from any kinks. These can often be observed during the use of the pressure washer and addressed accordingly to ensure smooth water flow.

• Assessing Water Source and Water Flow

The water source and its flow rate are another area to check. Evaluate if your source is supplying enough Gallons Per Minute (GPM) needed by the pressure washer. The GPM can be found in the instruction manual of the pressure washer. Purdue University provides handy resources on water flow assessment.

• Testing Nozzles and Clearing Blockages

Nozzles can often become obstructed, causing a drop in pressure. If you notice such a problem, consider clearing the blockage first and then run a test to see if the water flow has improved.

• Choosing the Correct Nozzle Tip

Ensure that the correct nozzle tip is being used according to the type of cleaning you are doing. Using the wrong type or worn-out nozzle tips could cause poor water flow. When needed, replace worn-out nozzle tips to keep your pressure washer functioning optimally.

• Checking O-Ring Problems

The outlet coupler and pressure washer wand both contain O-rings that might wear out over time. Check for any damaged or missing O-rings, which should be replaced as soon as they are found to be missing or damaged.

• Inspecting the Unloader Valve and its Spring

Check the unloader valve and its spring for rust. If it’s rusted, they need either adjusting or replacing. This is a key step in ensuring that your pressure washer operates at its best.

• Ensuring Proper Nozzle Attachment

I recommend checking that a nozzle is properly attached to the pressure washer spray gun. An improper attachment could cause low pressure or water leakage.

• Observing Proper Water Temperature

Ensure that the water temperature matches the manufacturer’s specifications. Incorrect temperatures may cause decreased pressure due to the unoptimized performance of the pressure washer.

• Checking and Adding Oil

This is applicable particularly to gas models. Make sure to check the oil level according to the manufacturer’s guidelines and add oil if found necessary.

• Pump Inspection and Cleaning

Regularly check your pump and clean the pump filter if necessary. Debris can block the water flow and result in reduced pressure. By keeping the pump and its filter clean, you can sustain a high level of performance.

• Adjusting Belt in Belt Drive Pressure Washers

For belt drive pressure washers, a slack or slipped belt needs to be tightened or replaced if necessary. Inadequate tension in the belt can severely affect the pump’s performance, leading to reduced pressure.

• Checking Hoses and Pipelines for Proper Fitting

Ensure that the hoses and pipelines are properly fitted and tightened to avoid air leakage. Leaking air can effectively rob your pressure washer of its maximum potential, dropping the pressure considerably.

• Seeking Professional Assistance

If all troubleshooting steps have failed and pressure is still low, do seek professional help, especially if your pressure washer is under warranty.

Experts can diagnose and solve the issue effectively without risking further damage. Always remember, your pressure washer should be functioning at its best to give you the cleaning power you need.

Pressure Washer Stalling: Common Causes and Remedies

• Triggering the Pressure Washer

Embracing the role of a pressure washer to clean different surfaces is undeniably satisfying. However, frustration can creep in when the washer stalls each time the trigger is pulled. It’s a disruptive hitch often linked to faulty internal components, typically the unloader valve.

• The Role of the Unloader Valve

The unloader valve is an indispensable part of a pressure washer. It’s essentially the powerhouse that controls both the pressure and the flow of water. A faulty unloader valve can trigger the pressure washer to stall or shut down when the trigger is pulled.

• Factors Behind the Stalling

While the unloader valve tops the list of potential culprits causing the stall, it’s not the exclusive one. Other possible causes include a dirty or clogged nozzle. Simply, if the nozzle is blocked, water doesnt flow out as it should, leading to a sudden stall.

Likewise, a malfunctioning pump could be to blame. The pump circulates the water within the pressure washer, and if it’s not working properly, the washer might shut down when the trigger is pulled. Insufficient water supply is another potential cause.

• Preventive Measures: Maintenance and Cleaning

To fight off these problems contributing to pressure washer stalls, maintenance should be your friend. Regularly check the oil level, clean the air filters, and inspect the spark plug. Ensuring these elements are in optimal condition can prevent stalling issues.

• Safety Precautions

Working with a pressure washer requires a special degree of care. Always wear protective eyewear and gloves to safeguard against potential accidents. Besides, it’s critically important that the machine is properly grounded to prevent electrical issues.

• Consult a Professional

If none of the mentioned troubleshooting steps prove effective and the stalling persists, it may be time to call in the professionals. Contact the manufacturer for further assistance. They may recommend a certified technician or service center to diagnose and fix your pressure washer.

A handy resource for diagnosing pressure washer problems can be found at Pressure Washers Direct, a non-commercial educational site. It offers a wealth of knowledge and steps to fix common pressure washer troubles.

• Low Water Supply

A low water supply can cause your pressure washer to stall. It’s essential to have an adequate water supply feeding into your pressure washer. Always check the hose connection for any blockages and ensure the water source is fully open.

– Pump Problems

The pump is an equally vital component of a pressure washer, playing a pivotal role in the machine’s operation. Pump problems can be caused by a lack of water, debris blockages, overheating, and more.

– Dirty or Clogged Nozzle

A nozzle clogged with dirt and debris can easily cause your pressure washer to stall. I recommend regularly cleaning the nozzle to ensure it’s free from any obstructions.

• Regular Maintenance

Proper and regular maintenance can certainly extend the life of your pressure washer. From inspecting the oil level to cleaning the air filters and spark plug, these simple tasks can help prevent stalling issues.

Proper oil maintenance, for instance, can be a game-changer in your pressure washer’s performance. Low or soiled oil might create undue friction in the engine, causing it to stall.

• Safety Precautions

It’s important to handle the pressure washer with care. Don’t forget to use protective gear like eyewear and gloves. Ensure the machine is adequately grounded. Also, be cautious when working on heights or slippery surfaces.

• Consult with Professionals

When all else fails, consulting a professional or the manufacturer is a wise decision. This will help get to the root cause of the problem and find an effective solution. Moreover, it’s the safest option if you are not confident in handling complex pressure washer issues by yourself.