What Does an Unloader Valve Do on a Pressure Washer?

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When it comes to cleaning off large surfaces in your property, nothing beats a pressure washer.

You can use a pressure washer to clean off the siding on your house, your deck, and even concrete surfaces like your pathway, patios, and driveway.

In fact, many homeowners wouldn’t be without one.

Like any other machine, it’s a good idea to know how it works, so you’re ready if and when you ever have problems with it.

One of the most critical components of a pressure washer is the unloader valve.

But what does an unloader valve do on a pressure washer?

We know most homeowners are wondering the same thing, which is why we decided to talk about it in this article.

What Does an Unloader Valve Do on a Pressure Washer?

Knowing how your pressure washer works is essential if you want to overcome any problems you might have with it.

If you experience too little or too much water pressure, for example, you may have a problem with your unloader valve.

Before anything else, let’s start with the basics.

What is an unloader valve? How does an unloader valve work with the other components of your pressure washer?

Hopefully, this will help you better understand what might be going wrong with your unit.

What Is an Unloader Valve?

An unloader valve is a special type of device responsible for regulating pressure within an accumulating system, which holds loads until it’s instructed to release it.

In the case of liquid, it is used to help direct the fluid within specified pressure settings and unload the liquid from the pump back into the reservoir.

How Does an Unloader Valve Work?

Typically speaking, unloader valves are designed to respond to changes in pressure or flow.

An unloader valve will feed into an accumulating system when there is low pressure and unload into the reservoir when it detects high pressure.

How Does a Pressure Washer Unloader Valve Work?

Now that we have the basics covered, let’s move onto the specifics.

How does a pressure washer unloader valve work?

Within a pressure washer, the unloader valve and the trigger gun work together to form a valve system.

This system lets you control the water flow without having to turn the pump on and off in between use.

This can be really handy if the power switch isn’t always within reach.

This two-part valve system not only makes your pressure washer more convenient to operate, but it also makes it safer.

If you lose control of the trigger and nozzle for some reason, the water will simply shut off and start flowing back to the reservoir.

As you probably already know, when you press on the trigger, the water is directed out of the nozzle under high pressure.

When you release the trigger, the water is directed back to the reservoir or pump under very little pressure.

what does an unloader valve do on a pressure washer

Two Types of Unloader Valves

There are two ways in which your unloader might work, depending on whether it is a pressure-actuated unloader valve or a flow-actuated unloader valve.

Pressure-Actuated Unloader Valve

When you’re depressing the trigger with a pressure-actuated unloader valve, the gun’s valve is open, releasing the water through the nozzle.

This relieves pressure on the unloader valve and causes it to direct the water coming from the pump to the nozzle.

When the trigger gun’s valve is shut off by releasing the trigger, the pressure on the unloader valve increases, causing it to unload or recirculate back to the reservoir.

It works by using a simple valve and a mounted spring mechanism that opens when the correct amount of pressure is applied.

Flow-Actuated Unloader Valve

With a flow-actuated unloader valve, the valve system still works exactly the same way.

However, the action of the unloader is determined by flow rate instead.

In this case, a piston is used instead of a spring, and a reduction in flow will cause the unloader to start recirculating the water back to the pump inlet or tank.

Pressure Problems and Their Easy Fixes

Some of the most common problems you will encounter with your pressure washer involve the actual pressure of the water coming out.

A lot of these problems can be solved by adjusting your unloader valve or changing the nozzle.

If the fixes below don’t solve your pressure problems, your unloader valve may not be functioning properly.

In this case, you could try simply cleaning the valve.

If a good clean doesn’t fix the problem, hopefully, replacing the valve will.

After all, replacing your own unloader valve will certainly be a lot more affordable than paying for a new pressure washer.

Regulate Pressure Via Unloader Valve

You can control the pressure of your washer by adjusting the spring on your unloader valve.

Flow-Actuated Unloader Valve

If you have a flow-actuated valve, a spring holds the piston in the valve.

Tightening the adjustment bolt on the spring will reduce the water pressure that comes out of the nozzle.

Loosening the bolt will cause the piston to rise more easily, thereby increasing the resulting water pressure.

Pressure-Actuated Unloader Valve

However, if you have a pressure-actuated unloader valve, you’ll need to tighten the spring to achieve higher pressure.

Loosening the adjustment bolt will allow the water to unload into the bypass more easily, reducing the water pressure you can achieve through the nozzle.

When attempting to adjust a pressure-actuated unloader valve, you must have your pressure washer running and the trigger pressed down so that water is constantly flowing.

First off, you should loosen the adjustment bolt and then release the trigger and check that the unloader is still functioning correctly.

Then, press the trigger again and note the pressure reading once the water is flowing.

Only then should you start to tighten the adjustment bolt.

Check the pressure reading as you do so until the desired pressure is achieved.

Remember to always read the manufacturer’s instructions and stick to their recommended pressure settings.

If you have the right pressure gauge reading but still not enough water pressure, then it’s time to consider changing the nozzle on your pressure washer.

Changing the Nozzle

Nozzles are subject to wear and tear over time, so a loss of pressure may be fixed by simply replacing this one small plastic part.

If you change the nozzle to one with a larger opening for water to come out of, the pressure will decrease.

If you need to increase pressure, then you can invest in a smaller nozzle.

Know Your Unloaders

So, what does an unloader valve do on a pressure washer?

To put it simply, it regulates the pressure.

That’s a pretty important role when it comes to a machine that is all about the pressure!

Now that you know more about the unloader valve, you may be able to solve a lot of pressure problems yourself.