A pressure washer is a dream come true for many. You can forget about that long hose with no pressure, scrubbing and time on your knees. You can often forget about chemicals too. Instead, the pressure is so powerful that it can clean anything – from your dirty car to your sidewalk or driveway. However, pressure washers die when least expected and this is when frustration kicks in. There is not much to worry about if the pressure washer dies when trigger released. It is one of the most common problems you might face – apart from the traditional leaks.

Now, what are the causes associated with this issue? More importantly, is there a way to fix it or do you actually have to buy a new pressure washer? Here is everything you need to know about it.

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Pressure washer shuts off when trigger released? Here is why

According to Wikipedia, chances are the unloader valve is the cause if the pressure washer dies when trigger released. There is no other issue associated with this problem, so this is where you have to divert your attention. This mechanism is responsible for diverting the water in the pump into a loop as soon as you let the trigger go. Practically, water stays under pressure, even if it is not supposed to get out. In other words, it keeps you ready whenever you pull the trigger.

The whole process is reached with a piston head. It is located within the unloader valve. It shifts the water flow based on your actions. If the pressure in the pump is too high, the unit is supposed to shut off by itself or it might explode. This is what causes the issue. The pressure is too high and the engine simply cannot cope with it, hence the problem.

So, you know the cause. Now, how do you fix it?

Tools you need

There are a few tools you need to have around to get this job complete and fix a pressure washer. There is nothing special you have to purchase separately – you will most likely do with a few things that everyone may have around. Most importantly, you will need a wrench and a screwdriver. Other than that, it is worth getting some grease to finish the job, as well as some alcohol or kerosene.

Step #1

Use the screwdriver and the wrench to unplug the unloader valve. It is fitted in a bay – you need to take it off. There is a pin that locks it in. Take it off. Most manufacturers keep the valve visible, so you should not miss it. As for the pin, it is usually shaped like a U. Get the screwdriver in, pull it and unscrew it.

Step #2

The screwdriver is just as handy when you need to pull the unloader valve. You do not have to try too hard – pull it slowly. Look at the piston. When the pressure washer works, the piston should move back and forth. If it does not seem too loose, the pressure washer will turn off, so double check it.

Step #3

If your piston is sketchy, unplug it. Use the wrench, as it has a nut. Get both the spring and piston out and clean them with alcohol or kerosene. Once dry, you should grease it a little before putting it back. Even if the piston seems alright, it still pays off giving it a good cleaning.

Step #4

Double check the unloader valve setting to ensure it is in good condition. If it is too high, it will stop the engine when you release the trigger. After all, the valve must open up to send water back. If the valve fails to open, the high pressure will stop the engine. Therefore, pay attention to the setting and adjust it.

Step #5

There are times when the O rings might be responsible for the issue. If your pressure washer dies when trigger released, you might want to pay attention to this aspect as well. These O rings are attached to the unloader valve. They look like some seals. What do they look like?

If the O rings look a bit worn or torn, they are not good enough to ensure a good seal. In other words, they might cause issues with the unloader valve. Get some new ones and replace them. Make sure the size is identical. If you are not sure, take the old ones to a shop and ask for identical units.

Step #6

Since you are so far ahead into maintenance and cleaning, it pays off double checking every part for servicing. For example, check the pressure gun. If your gun is in a terrible condition, adjusting or fixing the unloader valve will not necessarily fix the issue. You may not have the result you expected. Perform the adjustment, but you may have to get a new gun too.

Step #7

When you are done with everything, turn the pressure washer on. What does it feel like? Does it work properly? It should work like new. If you still have problems, there are a few other things you could check or give an inspection to learn how to fix a pressure washer.

  • Take the air filter out, check it out and clean it
  • Get the spark plug out, clean it with alcohol and let it dry before reinstalling it
  • Take a look at the water inlet and make sure it is in good condition
  • Look at the wand screens and give them an inspection

Final words

As a short final conclusion, this fix should solve your problem. It is a quick fix that may take up to half an hour, even if you have no experience at all. If the pressure washer dies when trigger released, keep in mind that you do not really need a new one, but just a quick fix.

If the problem still persists and you have already tried all the extra fixes, you might need to see a professional service. However, doing everything in the right order should clear it out.

If you enjoy reading this article, do find out if you can use dish soap in pressure washer.