How does a hot water pressure washer work?

Before you settle on a hot water pressure washer, you need to understand how they work, or you might end up choosing the wrong pressure washer for you.

Today, we’re going to help you understand everything you need to know about pressure washers. By the end of this article, you should be able to find the perfect hot water pressure washer for you!

The science behind hot water pressure washers

A hot water pressure washer is great for many reasons. They are often better at removing dirt as compared to cold water pressure washers. Plus hot water ensures that you are not only getting rid of stains but also kills bacteria.

Both hot and cold water pressure washers have a pump that pressurizes the water and shoots it out at high pressure. But a hot water pressure washer goest through a boiler that heats the water before it gets shot out of the machine.

Hot water pressure washers do a better job at getting rid of grease because the heat makes molecules move faster and forces them to loosen their bonds. Once the molecules in the oil or grease break up, they become much easier to wash away.

Now that you understand a bit of the science behind hot water pressure washers. There are a couple of other things you need to know about pressure washers to help you further understand how they work.

The difference between Gas and Electric pressure washers

There are two types of hot water pressures out there – and we want to go ahead and cover them both in-depth below. We’ll start by talking about gas-powered pressure washers.

Gas-powered pressure washer

Gas-powered pressure washers are usually larger, heavier, and offer more power. It is best for heavy-duty and industrial cleaning.

Because of the fumes released from gas-powered pressure washers, it’s best to use these only outdoors.

They are more costly than electric pressure washers. There are also ongoing costs for fuel, oil, and maintenance. It requires higher investment and more commitment.

Electric pressure washer

An electric pressure washer is usually smaller in size, lighter in weight, and offers less power. You can use an electric pressure washer indoors or outdoor. Just make sure you have an outlet you can plug it in.

Electric pressure washers are best for residential or home use. It’s great for washing cars, decks, the exterior of your house, the gutters, and some interior objects.

Because it offers less power than gas-powered pressure washers, it is usually more affordable. Electric pressure washers also need little to no maintenance.

What do the GPM and PSI on a pressure washer stand for?

If you’ve seen a brochure for hot water pressure washers before, you’ve probably encountered the terms GPM and PSI. But what’s so important about these terms?

PSI stands for pounds per square inch. The PSI refers to the amount of pressure per square inch that pushes the water out of the machine.

It is directly related to the cleaning power of the pressure washer. The higher the PSI, the stronger the cleaning power of the machine.

GPM stands for gallons per minute. It pertains to the amount of water coming out of the pressure washer per minute. It basically refers to how fast water comes out of the machine.

A lower GPM means less water comes out of the pressure washer at a time and vice versa. A higher GPM will help you get rid of dirt much faster.

The PSI and GPM are usually directly proportionate. The higher the PSI, the higher the GPM will be as well.

How to know which PSI level is correct for the job

Hot water pressure washers with a PSI between 1000 and 1900 are usually enough for light residential cleaning. It’s great for cleaning vehicles, sidewalks, patio furniture, stairs, or even your BBQ grill.

Note: do not use a PSI higher than 1900 for your cars because it may damage the paint.

For stains on your driveway, garage floor, or deck that are more difficult to remove than usual, you may need a pressure washer with a PSI of 2000 to 2900. That is enough pressure for more heavy-duty residential cleaning.

Pressure washers with a PSI higher than 3000 are mainly for professional commercial or industrial use. A PSI of 3300 and above is great for paint prep, cleaning industrial equipment, boats, ATVs, and other surfaces that may need extra heavy-duty cleaning.

The difference between pressure washer nozzle tips

Both hot and cold water pressure washers make use of different nozzle tips. You’ve probably seen a couple of different colored nozzles that come with pressure washers — and no, it isn’t for design purposes.

Each color identifies the angle at which the water from your pressure washer is sprayed.

You’re probably thinking any nozzle tip works fine—think again. The wrong nozzle could end up damaging your property and cost you a lot of money for repairs. This is why we’re here to help you identify the difference between each nozzle!


A red nozzle tip shoots a straight jet of water at zero degrees. Its spray covers an area about the size of a quarter and does not fan out at all. It offers maximum blast but may also result in maximum damage if used incorrectly.

This nozzle is rarely used because it would take so much time to get large surfaces cleaned with this nozzle. But it would be great for pinpointing certain problem spots. Do note that it isn’t advisable to use this nozzle on your car.


The yellow nozzle tip shoots water at 15 degrees. The spray of a yellow nozzle covers a larger area than a red nozzle but is still small. It’s great for stripping paint and getting rid of dirt from smaller surfaces such as car wheels.


The green nozzle tip shoots water at 25 degrees. Because the spray of the green nozzle is much larger than a yellow nozzle, the pressure is weaker and more spread out. It is the most commonly used nozzle in households. It’s great for cleaning boats, cars, furniture, sidewalks, and driveways!


The white nozzle tip shoots water that fans out at 40 degrees. It covers a much larger area than the green nozzle and has low pressure. It’s great for cleaning surfaces that are fragile such as windows.


The black nozzle tip covers a much larger area with a spray that fans out at 60 degrees. It has the weakest pressure and is usually used for soaping.

Why Hotsy Equipment Has The Best Collection of Hot Water Pressure Washers

Now that you understand how pressure washers work, you finally know everything you need to choose the right pressure washer for you. This is where Hotsy Equipment comes in.

Hotsy Equipment offers a wide collection of hot water pressure washers. We’ve got everything, from gas-powered to electric pressure washers and they even offer different models with every pressure level on the list! We are the #1 pressure washer store online, and offer detergents, cold water pressure washers, and other products you need to get the job done right.

So whether you’re looking for a hot water pressure washer to clean your car or a heavier duty pressure washer that is sure to get rid of even the most stubborn of stains —Hotsy Equipment has everything you need to get the job done!

Go through our catalog and grab the perfect hot water pressure washer for you today!