Pressure Washer Shuts off when Trigger Released (SOLVED)

pressure washer shuts off when trigger released
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If your pressure washer shuts off when the trigger is released, it has a problem with the unloader valve. There are a few issues with your unloading valve that causing stalling the engine pump. Troubleshooting of this problem is pretty simple and you can do it yourself easily.

We are going to discuss the troubleshooting procedure step by step. Keep reading the article to learn those steps.

Required Tools and Items:

  • A screwdriver
  • A wrench
  • Alcohol/kerosene
  • Grease

Step One

Take a wrench and a screwdriver to unplug the unloader valve from its bay. First of all, unplug the valve retaining pin that locks the unloader valve with its bay. Typically, most of the pressure washer manufacturers keep the unloader valve visible. Even if you have the most powerful pressure washer like the best 3000 psi pressure washers, no need to worry to locate the retaining pin.  The retaining pin is something like a U-shape pin (common shape for most of the pressure washers). Insert your screwdriver inside the retaining pin and pull it up to unscrew the pin.

Step Two

Now, use the screwdriver to pull the unloader valve from its bay. A gentle pull is enough to do that. One of the major parts of the unloader valve is its piston that controls the pressure retention. This piston moves forward and backward when you run the pressure washer. If the piston can’t move freely, your pressure washer shuts off. So, inspect the piston whether it is moving freely or has some issues to move.

Click on the Link to Read>>>  Homdox Pressure Washer Review

Step Three

If the piston is moving freely, skip this step and go to the next step. If your piston is not moving freely, you have to work on it. Unplug your piston from the unloader valve. Use your wrench to unscrew the nut that fastens the piston with the valve. Unplug the spring and piston from the unloader valve. Now, clean the spring and piston with alcohol or kerosene. After that, grease the spring and piston with good silicone grease. Now, set them back to their respective places. This will allow the spring and the piston to work smoothly.

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Step Four

The unloader valve has a setting to produce pressure depending on your job. Check the valve setting to ensure it has a perfect setting. Maybe, your unloader valve has a too high setting that’s stacking the engine when the trigger is released. Your unloader valve must open up to cycle water back to the inlet side. When the valve fails to open up, it builds up high pressure that stalls the engine. So, adjust your unloader valve setting if required.

Step Five

Sometimes, pressure washer shuts off due to the problem with the O-rings. Your unloader valve has  O-rings that are generally known as washer or seal. If the O-rings are torn out, deteriorated, or in a poor state that is not enough to seal the oil pump, it may fail your unloader valve to work properly. Replace the O-rings with exact size ones. This will ensure proper sealing of the oil pump.  Check O-rings on Amazon

Step Six

Inspect the pressure gun for its serviceability. If it is not in working condition, only adjusting the unloader valve may not bring the perfect result you are looking for. Adjust your pressure unloader valve and consider buying a new gun as well. Check New Gun on Amazon

Step Seven

If you have done with the abovementioned steps but the problem remains as it were, try the followings:

  • Inspect and clean the air filter
  • Clean the spark plug with alcohol
  • Inspect the water inlet
  • Inspect the wand screens

If everything is working fine but the problem remains, you can go for a local expert or consider buying a new unloader valve. But if you are fed up with your present power washer, you may follow our buying guide on the best 3000 PSI pressure washers. 


Using a machine with trouble kills your mental serenity and creates instability. Take care of your pressure washer so that it can care for you in return. We hope that this article on “pressure washer shuts off when trigger released” was a bit helpful for you.


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20 thoughts on “Pressure Washer Shuts off when Trigger Released (SOLVED)”

  1. Thanks to this article I saved a bunch of money by not going to a professional technician and was able to complete the repair midway into a job and continue on to finish the job same day with no earnings lost. Thank You so much for this detailed information. It has helped me out tremendously. Aaron P.- WA, USA

  2. What if the pressure washer idles fine, but then shuts off immideately after you pull the trigger? I have a Ryobi 3100 model and I have cleaned the carburator, I have checked the unloading valve and it looks good, I have fresh fuel, changed the oil, cleaned the spark plug, but it keeps shutting off once I pull the trigger.
    Any thoughts

    1. Hi Manos,
      Seems that it is time to replace your carb kit. Have you replaced your carb kit before? How long have you been using this Ryobi? Sometimes, an aged carb kit may look fine but not capable of supplying fuel to the piston. What about your O-rings? Is that in working condition? Either you replace your old carb kit and O-rings or consult with a local expert.

      1. I have simpson 3000psi when I turn on it’s come one with press of gun but then it’s go out. If I do not press the gun then it have lots of pressure build to it as soon as I press gun it’s release the pressure. Can you let me know what can I do to fix it.

  3. Thank you for taking the time to reply.
    It’s about 8 years old but it has been barely used. It’s been used max once or twice every summer season.
    Which O-rings are you referring to? The unloading valve ones? I’ve checked those and at least visually they look OK. I was wondering if it’s possible that there’s an issue with the pump which I don’t know if it’s serviceable at all.
    Thank you again!

    1. Yeah, we were referring the ones on unloader valve. They might have been ok as you visually found so. Have you found any abnormal pressure decreasing? If your pressure washer is not capable of generating its rated/working pressure, there might have been issues with your pressure pump. But, a bad/faulty pump does not shut down the engine. You better consult with a local expart. We appreciate your patience for our reply.

  4. Clayton Crochet

    Hey, pressure washer will start fine when I’m holding down the trigger. It will run all day when I’m pulling the trigger, but when I let it go, it’s just a matter of seconds before it dies out. Sounds like the unloader valve? Thanks

  5. Have an odd one for you…pressure washer runs fine but gun only trickle sprays when squeezed…but if I choke the engine then return to full power while holding gun on them it goes to full strength spray until I let off the trigger.

    Found this out while my wife was helping me try to troubleshoot.

    Any ideas? I tried to keep this brief. Thank you guys.

    1. Hi Mike,
      Clean your carb kit with alcohol or kerosene. Your problem is the result of carburetor malfunctioning. Do not forget to check the air & fuel filter for clogging. Hope it helps.

  6. Eduardo Zavala

    Hola, tengo una Ryoby 1600 psi electrica modelo 141612,el problema es que se prende y se apaga sola aunque no jale el gatillo, que problema tendrá??

  7. Pressure washer works fine until I release the handle, motor stops ok but just hums until it trips the circuit breaker. whats up with that?

    1. Hi Rick,
      How old is your power washer? Is it an electric washer or gas-driven?
      If it is an electric power washer, check the serviceability of the motor coil & lubricate the path in which the motor orbits.
      If it is a gas-operated power washer, check the pump oil and the said path. If found bad, change the engine oil and lubricate the path. Hopefully, your problem will be solved. Thanks…

  8. I have a Craftsman 2450 PSI washer. It will run with no hoses attached. It will not start if water is supplied unless I squeeze the trigger on low. It will run fine as long as I squeeze the wand trigger, and only on low. If I let go of the trigger or switch to high, the engine stalls out. Any suggestions? The piston on the unloaded is operating, and the little opening on it looks clear. Is there a passage where the unloader is inserted that may be clogged? Thanks.
    If I have the engine running and connect a water supply and no hose on the outlet, the water does spray out the output at a high velocity. I believe the wand and nozzle are clear, as water will flow on low and high settings with the engine off.

    1. Update. If I adjust the pressure on the unloader valve low enough it will stay running with the trigger released, and with the nozzle set on high.

  9. I have a Generac power washer That gets hot and shuts off after 10 seconds. Can you tell me what to look for that would Create this problem

    1. Hi John,
      We are not clear about your query. Does your power washer gets hot and turns off within 10 seconds of operation? Or does it turns off after 10 seconds of getting hot ( it maybe running for a while)? Anyway, it would have been better for us to reply had we understood the issue.
      Probable cause & solution: There is a thermal protector valve for the pressure washer pump that relieves heat. Once the valve becomes faulty or unable to do its part, the power washer gets hot and turns off. In this case you need to change this thermal relief valve.
      Another possible cause is faulty unloader valve that may fail to regulate pressure. In that case you need to adjust the unloader valve. If the valve still fails to regulate the pressure, replace it.
      We recommended you to read your owner manual to seek whether this failure is included in the troubleshooting section. Thanks…

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