Can You Start a Pressure Washer without Water? Running a Pressure Washer Without Water

Published Categorized as Info
Hey! This site is reader-supported and we earn commissions if you purchase products from retailers after clicking on a link from our site.

Pressure washers are very powerful devices that are used for cleaning dirt or grime off surfaces. This surface can be your driveway, bodies of automobiles, barbecues, or outdoor furniture.

A common question asked about pressure washers, is whether you are able to run them without water, and so, this article will provide you with all the necessary information on the question.

How Do Pressure Washers Work?

I want to first present the mechanisms involved in pressure washers, which should help you understand the importance of water, and why starting them without may not be the best idea.

When water flows through the pressure washer, with its cold temperature, it is able to lower the temperature of the motor whilst also lubricating components and preventing wear and tear. Experts quite simply describe using a pressure washer without water as a recipe for disaster.

Pressure washers contain a water inlet, water pump, motor, hose, gasket, and cleaning attachments (nozzles, etc.). Pressure washers are simple machines that help make cleaning work easy, saving time and money.

Pressure washers are designed to forcefully release water from their nozzle at high pressure and speed to allow the water to clean surfaces. According to Pascal’s Law of Physics, when you apply pressure at a point in a fluid within a container, the result will be an even distribution of pressure throughout the fluid.

In this case, the law is applied to water in motion. As water flows from the source into the pressure washer motor. The pressure washer heats the water to a temperature of about 70 degrees Celsius, before pushing it to an exit nozzle. The pressure of the water is increased by the pump, motor, and nozzle, each playing a part. This results in the desired high-pressure and speedy water exiting the washer.

In the case that the pressure washer has a gasoline motor/engine rather than an electric one, there will be a set of cylinders and a piston attached to a pull cord that gains momentum from the motor. There are also plungers in the pump which are connected to a crankshaft that will suck and eject the water.

When the plunger goes up, water is drawn into the pressure washer and then it will move into the unloader via a check valve. The moment the trigger is activated on the unloader, pressurized water will pass through the nozzle.

Can You Run a Pressure Washer Without Water?

Let’s get right into starting a pressure washer without water. Yes, it is possible to do so, but it is certainly not advisable. If you start your pressure washer without any water hooked to it, you will be taking a huge risk.

The damage done to the pressure washer will be quite immediate, and potentially devastating, especially to the inner components of the pump. As the pressure washer is activated, the pump mechanism will be the first to undergo damage. Not long after the pump, other components will begin to wear down faster than they should.

The more frequently you start the pressure washer without water, the sooner the damage will accumulate, and the shorter the lifespan of the device will become. In only a few seconds, a pressure washer running without water will cause the pump to work harder than it should.

Pressure washer pumps are designed to operate with water flowing through it, they essentially take the water in from the supply hose and push it out through the nozzle of the pressure washer. Without water flowing through it, the pump doesn’t have its lubricant (water) that helps to keep it cool. This, therefore, results in the pump wearing down quickly because of the lack of lubrication in dry starting.

Another possibility is that when starting the pressure washer without water, you may cause the motor to become damaged, Due to the pump having to work harder, the motor will be working under a heavier load, trying to turn a pump that’s under a lot of friction. This ultimately will lead to cause the motor to lock up or overheat significantly.

It’s very likely that in a short amount of time from starting your pressure washer without water, it can go from being in perfect working condition to having a damaged pump, motor, seals, gaskets, and other components. It’s clear, that you shouldn’t start the pressure washer without water flowing through the pump.

Diagnosing the Damage from Starting Your Pressure Washer Without Water

Though it’s advised not to start your pressure washer without water, you may have already, and so what if you have accidentally done it and you’re wondering how you find the damage to the pressure washer?

Although damage to the motor and pump could be immediate, you will need to carry out a comprehensive diagnosis to establish the extent of the damage. The best way to do this is starting the machine and testing it for optimal functioning – with water of course!

If water does not come out through the nozzle of the pressure washer, this is a clear indication that the pump is damaged. And the only real way around this is to replace the pump with a new one. The problem is that this may not necessarily completely fix the pressure washer.

If the pressure washer’s motor does not sound right, or it shuts off, this is a clear indication that the motor will need to be repaired or replaced as well.

If damage is done to the motor or pump, and they need replacing, it’s highly likely that other components like gaskets and seals are going to be damaged, which may lead to the need to rebuild the whole machine.

How much is this going to cost? I’m not sure entirely because it will vary depending on the size of the pressure washer and the number of components that need to be replaced, but it’s all adding up fast right! It may end up becoming so expensive that you’re better off buying a new pressure washer.

Using a Pressure Washer with a Small Amount Water

I know for a fact that sometimes water may be hard to find, and you may not have access to a water faucet. So, can pressure washers run with little water? Yes, some pressure washers will be able to run off very little water, for a short time that is, as long as this water supply is consistent.

When in doubt about whether you have enough water for your pressure washer, you shouldn’t risk it and use it. You must be absolutely sure you have enough water otherwise you are risking the likelihood of wear to components.

In some situations where water is hard to come by, it is possible to run your pressure washer or little water, though it’s important to understand pressure washers require a lot of water to run smoothly.

One way to ensure that your pressure washer doesn’t start without water in the pump is by using a pressure washer tank or a rain barrel as the water supply. If neither of these is available, then using an external pump to draw water out of a nearby lake or river is a good idea, again, if possible!

Here’s an example of a Kaercher suction hose readily available on Amazon which will allow you to pull water from a tank, barrel, bucket, lake, or river!

Karcher Water Suction Hose with Filter for Karcher Electric...
612 Reviews
Karcher Water Suction Hose with Filter for Karcher Electric...
  • Connects to your Kärcher pressure washer's water inlet
  • Allows you to use ponds, water buckets and tanks as an alternate source of water
  • Includes filter to prevent debris from entering the pressure washer
  • 9.8 feet (3 meters) in length. Max water temperature 104° F

Last update on 2022-05-31 at 17:15 / Affiliate links / Images from Amazon Product Advertising API

Below are a couple of useful YouTube demonstrations that talk you through how to use a pressure washer without a water supply!

Pressure Washer Maintenance Practices

Running a pressure washer without water is certain to cause damage to the pressure washer, whether that is slightly or significantly is down to the length of time the pressure washer is on. Water is life to every living thing, and so, it should also be seen that way with pressure washers. Aside from a water supply, there are other steps you should take to ensure that your pressure washer remains in working condition,

These pressure washer maintenance practices include:

  • Applying detergent: 
    You should not use a strong detergent when cleaning your pressure washer because you may damage it, especially the internal components. Corrosion is bad news for the moving parts of a machine.  
  • Monitoring water pressure: 
    To avoid a sudden drop in pressure and damage to valves, you should flush the inlet pipe to remove air before starting the machine every time.
  • Lubricating the pump:
    Put lubricating in your pressure washer regularly. It guards against overheating of moving components such as pressure pistons.
  • Using correct fuel: 
    Do not risk using the wrong type of fuel. You don’t want to run down your machine ahead of a long cleaning day.
  • Cleaning the carburetor:
    Do this as often as necessary. For pressure washers that use gasoline, there are filters on the fuel line leading to the motor. Cleaning the carburetor to rid it off obstructions. In some cases, a replacement will become necessary.

FAQs (Frequently Asked Questions)

What happens if I start my pressure washer without water?

If you start your pressure washer without water, you’re likely to cause some serious internal damage. The pressure washer’s pump will be the first to undergo damage as soon as the device is activated. The pump relies on the lubrication from the water to remain cool during operation. Without this lubrication, and without water being pumped, the pump will require the motor to overwork, and this will lead to overheating and premature wear. Not long after the pump and motor, other components will begin to wear down faster than they should.

How do you use a pressure washer without water?

It is strongly advised to never use your pressure washer without a water supply. If you don’t have water, you can use a washer tank or a rain barrel as the water supply. If neither of these options is available, you could draw water out of a nearby lake or river using a suction hose.

Does a gas pressure washer need water to start?

All pressure washers need water to start, it doesn’t matter if they’re electric or gas powered. They shouldn’t run without water otherwise you risk internal damage to components, especially the pump and motor.

Can you use a pressure washer from a bucket?

You can use a pressure washer from a bucket of water if you have a suction hose to pull the water out the bucket. This is of course better than using no water, but it may not be enough water as pressure washes require a large volume of water to operate. You will find yourself having to constantly stop/start so that you can refill the bucket to operate the pressure washer.


If you have any questions about using a pressure washer without water, please leave a comment below, so that someone can help you!

Leave a comment

Your email address will not be published.