Why does my pressure washer keep pulsing? Helpful tips


One of the more annoying feelings when using your pressure washer is the pulsation of pressure. Because of this pulsating pressure, it is almost impossible to use the machine. And you must fix your pressure washer, so the problem does not worsen or even damage more components.

Why does my pressure washer keep pulsing:

Your pressure washer pulsing can be due to various reasons. It can not get enough water. Second, there can be kinks, leakage, or blockage in the hose. Third, the pressure washer nozzle can be damaged or wore out. Fourth, air can be trapped inside the pressure pump and lead to your pressure washer’s pulsing.

Why does my pressure washer keep pulsing? Helpful tips 1

How to Troubleshoot a Surging Pressure Washer?

Troubleshooting a surging pressure washer starts with checking the nozzle for any dirt. Next, adjust the unloader valve. Next, see if there is any blockage that is trapping the air inside. Next, examine the hose for any leakage. And check the water supply and valves of your pressure washer.

Surging is a decrease in the water pressure of your pressure washer after you turn it on. If the water pressure decreases after running for a few minutes, it means that your machine has a surging issue. There can be many factors that cause this problem. You can use our troubleshooting steps to find and fix the issue.

Step 1: Check the nozzle

Most of the time, the nozzle of the pressure washer is the main issue behind the surging. First, check the nozzle of your pressure washer. If there is any dirt inside the nozzle, clean it with the nozzle cleaning kit. Make sure that your nozzle isn’t partially plugged. That can also cause a loss in water pressure. If your nozzle is worn out, replace the nozzle to regain the maximum pressure of your pressure washer.

Step 2: Check the unloader valve

Check the unloader valve. This valve is used to divert the water flow from the pump towards the bypass. The unloader valve can also be a reason the surging pressure of water comes from the pressure washer’s nozzle. This unloader valve is situated above the water inlet. Locate the unloader valve and check if there is any blockage. It could also be worn out.

You can adjust the unloader valve in small steps to increase the pressure of the washer. Connect the pressure gauge when adjusting the unloader valve in order to prevent the pressure from getting too high. During adjustment, ensure that the machine is running and pull the trigger to allow water to flow through the machine. If your machine is still producing low pressure after adjusting the unloader valve, then your valve could be broken and in need of replacement.

Step 3: Check the hose and filter

After adjusting the unloader valve, check the inlet hose for any issue that could be the reason for the low water pressure. Clean the hose completely. If there is any leakage in the hose, then you need to repair or replace it. There could also be some air trapped in the hose. You can remove this air by pulling the trigger to make the water start flowing.

It is essential to supply most pressure washers with at least 0.9 gallons of water per minute. This means that the diameter of the supply hose should be ¾ inches or bigger, to avoid any surging in your pressure washer. If the washer’s pressure keeps pulsing even with a ¾ inch diameter hose, then check for any blockage in your hose. Loosen the hose from the inlet valve of the pressure washer and inspect and clean any debris from the inside of the filter.

Step 4: Check the water supply and pump

Sometimes, the water source may not be supplying an adequate amount of water to your pressure washer. This can lead to a pulsating pressure. If an inadequate amount of water is not the problem, then examine the pump packings. If they are worn out, then replace them as required.

Step 5: Check the valves

The last step in troubleshooting a surging pressure washer is to check the valves. If the inlet or the discharge valves are not in working condition, then replace them as needed. The inlet valve lets the water into the manifold, then from there, the inlet valve closes, and water is pushed downward towards the discharge valve by the plunger. This discharge valve releases the water. It is located on the outer side of the pump.  If your valves are in good working condition without any issues, check the valve’s spring. It could be broken and, in that case, need to be replaced.

How do I fix my pressure washer surging?

In general, first, check that the hose is free of any kinks or blockage. Ensure that connectors and hoses are correctly connected and fitted. Turn the spray wand and faucet to the highest setting to deliver maximum output pressure. If your pressure washer is still delivering fluctuating pressure, turn off the machine and remove any air that is trapped in the pump. To do this, keep only the hose connected to the pressure washer and turn on the water supply to allow the water to run through the pump for at least 20 seconds.

If this didn’t help, check for any debris inside the nozzle. Clean if needed. Also, check all the filters and clean them when needed.

How do you fix a pulsating pressure washer?

To fix a pulsating pressure washer, first, check for kinks or blockages. Check and fix any air that is leaking through the inner plumbing of your pressure washer. Next, examine the pressure washer pump because sometimes air gets trapped in the pump, causing the water pressure to pulsate. Also, check the nozzle, and if it is worn out, then replace it.

You can fix a pulsating pressure washer problem by following these steps:

Step 1: Fix any kinks or blockages

If the pressure of your machine keeps pulsing, it could mean that your water flow is restricted. Before using your pressure washer, make sure that there are no kinks or leaks in the hose. Any leakage in the hose will drop the pressure. Sometimes, lime in the water or dirt gets stuck inside the inlet or discharge valve after the pressure washer after prolonged usage. To dissolve lime buildup, you can use vinegar.

Sometimes, a significant amount of detergent builds up in the detergent section. That can also be a potential reason for the pulsating pressure.  Distilled vinegar can be used to clear detergent and any dirt or debris that is stuck in the detergent suction.

Step 2: Fix any air leakage

If air is entering the pressure washer, this can lower the water pressure. Disassemble the pressure washer and try to find where this air is sucked in. The most likely location is one of the seals. Seal the source of the leak, and then reassemble.

Step 3: Fix the pressure pump

Sometimes, the air gets trapped in the pump. You can fix this problem by first disconnecting the hose of the pressure washer. Next, turn on the pressure washer to allow water to flow through the hose. Then assemble the machine again and test it out to see if that fixes the pulsating problem. Also, make sure that the water supply to the pump is enough to maintain the outlet pressure.

The pressure pump is often the reason behind pulsating water pressure. With time, dirt and debris gather inside the inline filter. Depending on the water source you use, this can increase quite quickly, causing the pulsating pressure. To get rid of this problem, clean the inline filter. If your machine does not have any inline filter, then add one.

Step 4: Replace or fix the nozzle

A dirty or worn nozzle is another reason for the pulsating pressure. You can recognize a worn-out nozzle due to an unusual spraying pattern. Nozzles wear out after using them for some time, and then they need to be replaced. If the nozzle is not that old, you should try to clean it first. You can use another nozzle to check if this fixes the problem

Why is my pressure washer revving up and down?

In general, the reason behind your gas pressure washer revving up and down is probably a fuel problem. This can be due to dirt in the carburetor or the screws not appropriately tightened. Other common reasons are a problem with the spark plug or air filter.

You gas pressure washer revving up and down is a common probolem. We will show the most common reasons and how to fix them:

Reason 1: Bad Gas

To maintain your pressure washer’s performance, you must regularly change the gas and oil of your pressure washer. When you keep gas in the tank for more than a few months, it can get bad. This can lead to your pressure washer revs up and down. If this is the case, replace the gas in your tank. And use a fuel stabilizer when you do not use your machine for an extended period.

Reason 2: Carburetor issue

If the carburetor of your pressure washer is not adjusted correctly, it can cause the engine of your pressure washer to rev up and down. Sometimes the screws of your carburetor are not tightened properly. To fix this problem, turn on your pressure washer and then, using a screwdriver, tighten the screws until your pressure washer runs smoothly.

If this does not help, remove the carburetor and clean it. You can use a carburetor cleaner for this.

Reason 3: Spark plug

If your pressure washer is still revving up and down after this, check the spark plug of your machine. First, examine the wires of the spark plug. If they are loose, tighten them. Also, check if there is any corrosion at the edge of the spark plug. You can remove this corrosion using a metal brush. If it is widely spread, replace the spark plug.

Reason 4: Air filter and fuel cap

Your pressure washer may also rev sporadically because of an air blockage. In this case, clean the air filter to get rid of any dirt or debris stuck inside the filter. If your model has a paper air filter, replace it. Other types of air filters can be cleaned carefully. You can wash them, but let them fully dry before assembling them.

Also, check the vented fuel cap for clogs, and if there is any dirt, then clean it too to allow the air to flow freely.  

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