How Do I Fix My Pressure Washer Surging? With Helpful Tips


Pressure washers are perfect for cleaning your house, objects, and a variety of surfaces efficiently. High-pressure water is a strong force that can even remove tough stains. But when a pressure washer experiences a surging problem, it can hinder your work significantly. A surging pressure washer can have multiple causes. The first step to fix it is to do some troubleshooting.

How Do I Fix My Pressure Washer Surging:

Generally, the first step in fixing a surging pressure washer is to check that every hose is free of kinks or blockages. Ensure that the faucet is fully open, and check and tighten all the connectors. If your pressure washer still is still surging, check and remove any trapped air in the pump and hose. Check and clean the nozzle, the various filters, and the unloader valve.

How Do I Fix My Pressure Washer Surging? With Helpful Tips 1

Through this article, you will learn the reasons behind your pressure washer surging. I will show you how to troubleshoot and fix the most common reasons.

Why is My Pressure Washer Surging?

In general, the most common reason for your pressure washer surging is restrictions in the water flow. This can be due to a kink or blockage in the hose or a problem with the nozzle. Using a pressure washer on several surfaces can lead to a worn or clogged nozzle. Inspect the pump packings for any damage and ensure that the water source supplies an adequate amount of water to the pump. Another reason for surging can be some trapped air in the pump. Or stuck debris in the pump due to not having a hose filter inside the pump inlet.

If your pressure washer is facing a surging problem, there can be many reasons for it. I will list the most common causes and how to fix them:

Reason 1 – Surging pressure washer: Restricted Water Flow

One of the most common reasons for the surging problem in your pressure washer is a restricted water flow. Make sure that all connected hoses are free of kinks, leaks, and blockages. Also, ensure that all hoses are fitted and connected correctly.

Reason 2 – Surging pressure washer: Spray Nozzle

Another reason that can cause a surging problem is a clogged spray nozzle. Attach another nozzle and see if this fixes the surging problem. If this is the case, the nozzle is clogged. Use a very thin metal wire to clean it. You can also purchase a nozzle cleaning kit and use that to clean the nozzle inside completely. If that doesn’t work, replace the nozzle.

Reason 3 – Surging pressure washer: Pump Packings

Damaged pressure washer pump packings can also be the reason behind the surging problem. If damaged, they need to be replaced. If the packings are fine, check the water supply. Ensure that your pressure washer pump is getting enough water from the source at the required minimum GPM (Gallons per minute). If it is significantly lower, the pump can run hot and can lower the output pressure.

Reason 4 – Surging pressure washer: Trapped Air

If the water pressure is still shifting from high to low, it can be due to trapped air in the pump. Because of this trapped air, your pressure washer’s pump can’t produce enough pressure to push water out of the nozzle at the required settings. You can fix this problem by first disconnecting the hose of the pressure washer.

Let the water flow through the hose until all the air in the hose is gone. Reconnect the hose to the pressure washer. Turn on the pressure washer and let it run for some time. This should ensure that all the air in the pump is removed. Check if this has fixed the surging problem.

Check the inline filter. Over time, dirt and debris gather inside it. This can increase significantly after a while and limit the amount of water flowing to the pump. Clean the inline filter with an air compressor. I recommend adding an inline filter if your machine does not have one.

Reason 5 – Surging pressure washer: Damaged Unloader

The main purpose of a pressure washer unloader is to relieve the water pressure when the trigger is released, or the nozzle is blocked. Inspect the unloader that is situated above the water inlet. If it’s restricted, it can cause the pressure washer to surge.

Disassemble the unloader valve and clean the components. Adjusting the unloader pressure valve is a tricky process. The goal of the unloader valve adjustment is to find the spot where the pressure is maximum. And the pressure spike when you release the trigger is minimal. Remove the top, lock the nuts. Clip the pressure gauge and start tightening the spring. Once the spring is adjusted, engage the trigger to prevent blockages in the unloader valve. Adjust the knob until you find the spot where pressure is maximal, and the spike is minimal.

The unloader valve of a pressure washer has a tension spring responsible for releasing the pressurized water when the trigger is pressed. The tension spring is also responsible for decreasing the pressure when the trigger is released. By adjusting the pressure washer unloader valve, the goal is to find the ideal setting for the tension spring.

Reason 6 – Surging pressure washer: Garden Hose Filter

Sometimes, dirt and debris get stuck inside the pump, which can be the reason for the pressure washer surging. If your water system is coming from a more dirty source, like certain ground or rainwater systems, I highly recommend adding a garden hose filter.

This will filter out dust and dirt in the water before it enters your pressure washer. Also, ensure that your machine is using an inlet filter. If not, add one.

How to Troubleshoot a Surging Pressure Washer?

Generally, the first step in troubleshooting a surging pressure washer is to check the spray nozzle for any dirt. If the nozzle is fine, check the unloader valve for any damage or trapped air. Examine the hose and filter for any leakage or restrictions. If there are none, check the water supply and the valves of your pressure washer.

Surging is a decrease in the water pressure in your pressure washer. If water pressure decreases after running the machine for a few minutes, it means that your machine has a surging issue. There can be many factors that can cause this problem. Use to following steps to troubleshoot:

● Step 1: Check the Nozzle

Most of the time, the pressure washer’s nozzle is the main issue behind the surge in pressure. Check the nozzle of your pressure washer. Mount a different one and see if this fixes the problem. If that is the case, the nozzle is likely dirty.

If there is any dirt inside, clean it with a thin metal wire. Or use a nozzle cleaning kit. Also, make sure that your nozzle isn’t partially plugged in. This can also be the reason for the loss in water pressure. If your nozzle is worn out, then you need to replace the nozzle.

● Step 2: Check the Unloader valve

The second step is to check the unloader valve. It is used to divert the water flow from the pump towards the bypass. This unloader can also be used to troubleshoot a surging pressure of water coming out of the pressure washer’s nozzle.

The unloader is situated above the water inlet. Locate the unloader and open it to check if there is any blockage or if it’s worn out. You can adjust the unloader valve slightly to increase the pressure of the washer. Connect a pressure gauge when adjusting the unloader valve to prevent the pressure from getting too high.

During the unloader valve adjustment, check the pressure and find the optimal setting. The spike that you will see when releasing the trigger mustn’t be higher than 10%. A high spike can damage the internals of the pressure washer.

If your machine is still producing a low pressure after adjusting the unloader valve, then your valve might be broken and in need of replacement.

● Step 3: Check the Hose and Filter

After adjusting the unloader valve, check the inlet hose and filter for any restrictions that could be the reason for the low pressure. In this case, clean the hose completely. Ensure that the faucet you use is fully open.

It is also possible that the pressure washer or hose contains trapped air. Disconnect the hose from the pressure washer. Let the water flow until only water comes out. Connect the hose again to the pressure washer. Now pull the trigger and allow the water to flow for some time. This should remove any air from the system.

● Step 4: Check the Water Supply

Sometimes, the source may not supply an adequate amount of water to your pressure washer. This can result in cavitation or air bubbles at the nozzle. Cavitation is a clear sign that not enough water is reaching the pressure washer.

Most manufacturers mention they need 2 gallons per minute (GTM). But my experience is that with a lower amount, they still work fine. But ensure that you have at least a flow of 0.9 GTM. I recommend using a good hose. The minimal diameter should be ¾ inches to avoid any surging in your pressure washer. The longer the hose, the more important a good hose will be.

Suppose the water supply is not a problem. Examine the pump packings. If they are worn out, replace them.

● Step 5: Check the Pressure Washer Valves

The last step in troubleshooting a surging pressure washer is to check the valves. If the inlet or discharge valves aren’t in good working condition, they need replacing. The inlet valve lets the water into the manifold. The inlet valve closes, and water is trusted downwards by the plunger towards the discharge valve.

The discharge valve releases the water. It’s located on the outer side of the pump. If your valves are in good working condition, check the spring of the valve. It could be broken. In that case, replace it.

Recent Posts