Pressure Washer Loses Pressure When Trigger Pulled (Solution)

A pressure washer is a powerful utility tool that comes handy to keep homes, gardens, lawns, patios, and even your vehicles neat and clean. To speak the truth, it performs a myriad of jobs. However, sometimes you can feel frustrated to see that your pressure washer loses pressure when trigger pulled. This is embarrassing and utterly disappointing since the primary task of this machine is to deliver high pressure in an optimal state. 

The low-pressure production leads to many disconcerting complications. But how do you get a solution if your pressure washer shuts off when trigger is pulled? Well, we would recommend you a simple but effective way:

  • Detect the cause of the lost pressures
  • Troubleshoot the problem

Unfortunately, it’s easier said than done. But you shouldn’t feel worried at all. Yes, calm yourself down as we have piled up all the possible causes of a pressure washer losing pressure after pulling the trigger. 

But we haven’t stopped there. We have also compiled the most straightforward solution to these problems. So, it’s high time you became a professional plumber with us to see how it works so that you can fix the problem on your own when your pressure washer shuts off after a few minutes. 

Facts to Check If Your Pressure Washer Loses Pressure When Trigger Pulled

Sometimes it so happens that you pull the pressure washer trigger and start working with good pressure, and then suddenly, you lose the strength. Occasionally, there will be no pressure at all. At this, you can’t help yourself but stand and guess what on earth is going wrong. 

This happens most likely because the water flow rate fails to meet the water supply. But it’s only the top of the mountain. Many issues can cause a particular problem. 

At this point, most people will think about calling a maintenance specialist. But do you know that you can troubleshoot it all on your own with little effort and time? 

At first, let’s check the list of the causes that might be responsible for water pressure failure.

  • Clogged nozzles 
  • Restricted unloader 
  • Damaged valves 
  • Inadequate water supply 
  • Problems with the water flow rate

Now, let’s see if we can solve these problems with simple DIY projects to save time and money. Also, you will be free from any extra burdens. 

Checking the Nozzle 

The most common reason for low or no pressure after pulling the pressure washer trigger is a dirty or clogged nozzle. Also, it can be a worn-out or incorrect nozzle. So, whenever you find issues with water pressure during clean jobs, we like any expert technician would do, recommend you to check the nozzle through. 

Don’t know where the nozzle is located in a pressure washer?

It is, in general, located at the end of the pressure washer trigger wand. With time, it may get damaged, plugged, or worn out. But how do you know if the nozzle is working right or not?

The easiest way is to observe the nozzle spray patterns. If the nozzle is damaged or there is debris inside it, the spray pattern will be irregular.  Another indication is the gradual loss of pressure instead of sudden loss. 

Once you are assured that the problems lay in the nozzle, let’s make a move to solve it. 

Firstly, disconnect the nozzle from the pressure washer. Then use a professional cleaning kit to remove the debris, grime, and dirt from the nozzle. You should get the cleaning kit with the nozzle packages. Otherwise, you can buy one easily from the nearby DIY or hardware shops. 

Also, use a needle to remove debris from the nozzle tip to ensure optimal water pressure. 

However, if you still find the pressure washer not working correctly, the cause might be a damaged nozzle. In this case, you must replace it with a new one. The replacement for the damaged vent should be with a compatible one with the pressure washer. 

And lastly, ensure that the nozzle is connected to the washer tightly. A loose nozzle connection will also cause low-pressure production.

Restricted Pressure Washer Unloader

When the pressure washer nozzle doesn’t supply water through it, the unloader diverts the water through the bypass. It enables the pressure washer to stop water wastage. You can adjust the unloader to decrease or increase the water pressure rate coming out through the nozzle. 

There are two types of unloaders. They are as follows:

  • Flow-accentuated unloader 
  • Pressure-accentuated unloader

In general, the unloader is placed above the water inlet. You ardently need to check whether or not the unloader is restricted or worn out. 

If you observe any damage on the unloader, we recommend you to immediately replace it because it hampers the pressure output and may cause serious safety concerns. 

Solving the Unloader Issues

Any low or no-pressure issues of a pressure washer are most probably connected with the unloader. If you notice that your pressure washer stalls when trigger is pulled, you should manage it with the following steps. 

Unplugging the Unloader 

At first, disconnect the unloader from the pressure washer. You can use a screwdriver and wrench to dissemble it. 

Inspecting the Piston 

Now check the disk of the unloader. It should move freely to control the water pressure rate. But if the disc stops working correctly, the pressure washer will observe abrupt shutoff and low pressure. 

Cleaning the Piston

In case the piston doesn’t work correctly, you will require to perform a bit more task. Use a screwdriver to disconnect the piston from the unloader. Then, remove any grime and dirt from the piston and spring using alcohol or kerosene. 

Observing the Valve Setting 

In general, the unloader valve has a specific setting to control water pressure. When set at a high-pressure, it stacks the engine, which results in a low-pressure production despite pulling the trigger. 

You should set the unloader at an optimal state so that it doesn’t restrict the water flow and pressure. 

O-ring Inspection 

O-ring of a pressure washer is mostly known as a seal or washer. A deteriorated or worn out O-ring fails to seal the oiling, which results in low performance. So, to get e constant pressure, replace any worn-out O-ring with an exact one.

Pressure Gun

The unloader comes with a pressure gun attached to it. If you see that the pressure gun or wand is not working correctly, you should replace or upgrade it. 

However, if the pressure loss issue still exists, you may need to read on the following sections to troubleshoot them. 

Troubleshoot Damaged Valves

A pressure washer is a complex combination of different large and small parts. The lid is one of them. In reality, the pressure washer is equipped with several valves. Each comes in different sizes and with particular functions. 

The two most crucial valves responsible for pressure washer proper functioning and optimal water pressure are as follows:

  • Inlet valves: This is located at the opening of the water inlet and protects the inlet from exterior debris. 
  • Discharger valves: Located at the discharging point, the discharger valve is responsible for keeping the discharger and exhaustion area debris-free for smooth operation. 

If either of these two valves is damaged or worn out, which they often do because of external affairs and corrosion, the pressure washer loses its functioning power. If the inlet valve is damaged or clogged with grime or dirt, it reduces the water flow rate. As a consequence, the pressure washer can’t get enough power and water supply to maintain the optimal pressure. 

On the contrary, when the inlet valve is not in function, the plunger will push the water downwards near the discharger valve. As a result, it opens up to release the water. 

Hence, check both valves for debris or damage. If you find any grime, clean it with a dampened cloth and rubbing alcohol. However, if you find these valves damaged, you will require to replace them with the exact ones. 

Also, sometimes the valve spring may be found defective. In this case, you need to repair or replace the valve spring. 

Inadequate Water Supply 

In most cases, insufficient water supply is found, the culprit behind pressure washer losing pressure when the trigger is pulled. After all, how will the pressure washer deliver high-pressure if there is a shortage of water?

So, when your pressure washer stalls or gets no pressure, make sure it is getting adequate water. The water supply is related to PSI and GPM. Remember these two terms? PSI stands for the pressure applied on each pound, whereas GPM denotes the number of water gallons supplied by the washer in one minute. 

To get high-pressure from the washer, you must incorporate it with the desired GPM and PSI. If these two don’t cooperate, your appliance will face a shortage of water, resulting in a loss of pressure gradually. 

However, if you find that the water supply is adequate, you may need to check the pump and water flow rate as well. 

Water Flow Rate Issue and Troubleshooting 

If you put aside the water supply and nozzle issues, the most common cause for pressure washer stalling is an inappropriate water flow rate. 

To test whether your pressure washer is getting optimal water flow rate or not, turn on the pump and check the flow rate. If you see a lower flow rate of water, check for debris in the water path and remove it.

However, if you find flow rate satisfactory, you may need to look for other causes for which the pressure washer loses pressure after a few seconds. 

More Troubleshooting for Low or Lost Pressure 

As you see, we had already discussed the most common reasons why a pressure washer stalls when trigger is pulled. However, apart from these five reasons, there are two influential factors that you must consider for lost pressure. 

Now, let’s take a look at them. Oh, are you feeling bored? You may turn on your music system and quickly read through the remaining parts. We are almost there. 

High-pressure Water Hose 

Although a pressure hose with high-pressure isn’t a direct part of the washer, it will determine the pressure of your machine to a great extent. If you see pressure washer stalling despite having a high-pressure washer, it is an indication that your installed hose is an improper one. 

It will happen if the hose is wider than the compatible model with the pressure-washer. Hence, you will require to replace the high-pressure washer hose with a proper one. Furthermore, kinks or leaks may also cause low-pressure production. 

So, it is recommended that you purchase and set up a leak and kink-free pressure washer hose with your pressure washer. This will allow you to get optimal pressure for cleaning and watering purposes. 

Quality of the Plunger 

The quality of the washer plunger may affect the overall delivery of the washer. But it’s a matter of regret that most people neglect it. So, we advise you to check the plunger condition. If it is worn out, you may need to replace it. 

Remember, spare parts of the washer plunger are often made specific. So, instead of trying to find it in the local hardware shop, you should contact the manufacturer to get the same one for replacement. 


A pressure washer is meant to deliver optimal pressure to keep the surroundings clear. This is even more true at this time when Corona has spread as a worldwide epidemic. 

So, you must ensure that your home is clean and safe. In this regard, getting proper pressure from the washer is a must for you. But if you somehow find low pressure or lost strength from the appliance, you can always follow the troubleshooting techniques mentioned above. 

However, for your convenience, let’s once again take a quick recap of all problems and troubleshoots. Firstly, check for adequate water supply. Then you may need to inspect the water flow rate of the pressure washer. If you find both pressure washer water supply and flow rate satisfactory, you may look forward to the next issues. 

Pressure washer nozzle might get damaged, which is a reason as to why pressure washer loses pressure when trigger pulled. You may unclog the nozzle or replace it. After that, check the unloader and valve for debris or damage. If you notice any issue, solve it. 

Troubleshooting all these probable causes will keep you hassle-free and save money as well. If you, nonetheless, find the troubleshooting difficulty, rest assured that you wouldn’t have to be a professional technician to solve them. 

Only your willpower and effort are enough. So, say goodbye to pressure washer low-pressure forever and enjoy cleaning sessions.

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