How To Use Pressure Washer Downstream Chemical Injector?

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​Is it your first time using a pressure washer downstream chemical injector? No problem because we will teach you how to do it in this very short guide.

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​One of the best ways to use your pressure washer is to use it with detergents or chemicals. Of course, the question here is how do you put the exact amount of chemical cleaner into your pressure washer without damaging the pressure pump?

​You see, the problem with putting the chemicals directly into the reservoir is that it may cause the pump to corrode.

​That’s why it’s better to use a pressure washer downstream chemical injector to do this job. Now, if you have never used one before, then today is your lucky day-- we will teach you how to do that.

​Check out our guide below:

​Downstream Vs. Upstream Chemical Injector

​We mentioned above that we’re going to teach you how to use a downstream chemical injector for pressure washer. It’s pretty interesting to note that there is also an upstream chemical injector. What is the difference between the two, you may ask?

​Well, the downstream chemical injector is inserted into the pressure side of the pump. The main difference between a downstream chemical injector and an upstream type is that because of this characteristic, it doesn’t need a vacuum to bring the detergent to the reservoir. On the other hand, the upstream type does require a vacuum.

​That said, it’s actually safer for the pressure washer if you use a downstream chemical injector type.

​How To Use Downstream Chemical Injector For Pressure Washer

​Now that you know the difference between the two, the next thing that you’re going to learn is how to use the pressure washer downstream injector.

​We will teach you in the simplest steps how to make use of this device. That way, you can use it easily the moment you get your hands on one of these things.

​So here we go:

  • ​Insert The Injector

​The first thing to do is to know where to insert the injector. As mentioned above, you place it in the pressure side of the washer. In order to do that, you first attach quick couplers to the ends of the injector.

​From there, connect it to the connector between the pressure hose and power washer. Take note though that the process will change if you are using hot water. In this case, insert the injector in the hose reel area. This will ensure that none of the pressure washer parts will be affected by the harsh chemicals that you’ll put in. 

  • ​Allow The Vacuum Effect To Work

​Once the injector has already been placed, now you’ll need to wait for it to take effect. Just to give you an idea, these injectors make use of a Venturi type of effect that pushes the liquid inside the injector out and into the vacuum via pressure. At the same time, you’ll also want to use a low-pressure nozzle to help the detergent move.

  • ​Take Note Of Things To Avoid

​This is basically what will happen when you insert the injector to your pressure washer. Now, do take note that there are a few things that can stop the injector from working properly. First is if you use a high-pressure nozzle, so you may want to avoid doing that.

​Next is applying too much pressure using the pressure hose. If you do this, expect there to be a lot of resistance that will keep the water from going through the hose. Eventually, the back pressure will just push back the water to the injector.

​That being said, these are two things that you may want to remember when using your injector. These two conditions will stop the injector from working. Therefore, if you want it to continue functioning properly, remember to avoid these two situations.


​As you can see, it is actually quite easy to work an injector. All you need to do is follow the first step and wait. You also need to observe some of the situations wherein you may make the injector stop working and avoid them.

​Now that you know how to use a pressure washer downstream chemical injector, what are you waiting for?

​Buy one today so you’ll be able to experience just how useful one is.

Mattie Keyes

Hi there! This is Mattie. When I am not making DIY projects for my house, I spend most of my time researching and writing reviews of different products that you can buy online. I am an office worker turn full-time blogger, and I hope to help other homeowners like me on how to improve and reinvent your home using the best ideas and equipment.