Equipment

Pressure Washer Buying Guide: Choose the Right Pressure Washer for the Job

6/16/22
Grainger Editorial Staff

Pressure washers are powerful cleaning tools that can handle a variety of heavy-duty jobs. But with so many different options, how do you know which one is right for you? From electric to gas to choosing the right nozzle, our pressure washer guide will walk you through the basics to help you select the best pressure washer for your needs.

How Pressure Washers Work

Pressure washers can help you clean and restore a variety of surfaces from concrete, brick and siding to industrial equipment. Also known as power washers, pressure washer cleaners help reduce the need to scrub surfaces and use abrasive cleaning agents. A pressure washer’s powerful cleaning action comes from its motorized pump that forces high-pressure water through a concentrating nozzle, helping to break up tough stains like grease, tar, rust, plant residue and wax.

Knowing a few key terms will help you understand how pressure washers work:

PSI: pound per square inch
GPM: gallon per minute
CU: cleaning units, also referred to as cleaning speed

Before buying a pressure washer, always check its PSI, GPM and cleaning units. Selecting the correct PSI rating based on the type of task is crucial since higher PSI equals more force the water will have on the surface you're cleaning. You can easily damage many surfaces if the PSI is too high.

Pressure Washer Ratings

Light Duty: 0-1999 psi
Medium Duty: 2000-2799 psi
Heavy Duty: 2800-3299 psi
Industrial Duty: 3300 psi and more

Different Types of Pressure Washers

Pressure washers are available in two main varieties: gas and electric. Gas and diesel models offer you the power and mobility to tackle heavy-duty jobs like removing paint and cleaning driveways and sidewalks. Electric pressure washers feature an on/off switch and are typically quieter and more eco-friendly than gas models.

There are several different styles of pressure washers, including cart, carry, handheld, stationary, skid and wall mount. While corded electric pressure washers are more common, cordless pressure washers that run on batteries are available, making them highly portable and easier to store. Pressure washer water brooms and surface cleaners are great for cleaning floors, sidewalks, decks, patios, driveways and parking lots. Steam cleaners can sanitize hard surfaces on floors, machinery and equipment using very little water and no chemicals.

Water Type

Cold Water: Cold water pressure washers are great for most general-purpose jobs like facility maintenance, automotive work, hazardous material cleanup and more.

Hot Water: Use power washers with hot water for your toughest cleaning jobs. Hot water is more effective than cold water for removing mud, grime and other stubborn stains.

Steam: Great for surface preparation, refinishing, automotive maintenance and even thawing frozen equipment, steam pressure washers help remove oil and grease and produce less runoff than cold and hot water pressure washing.

How to Choose the Right Pressure Washer Nozzle

When selecting a pressure washer, it’s important to know which nozzle is used for different tasks and surfaces. Pressure washers often come with color-coded interchangeable nozzles or an all-in-one adjustable nozzle. Both types of nozzles allow you to change the angle of the water spray depending on the task. Adjustable nozzles are convenient because a simple twist is all it takes to change the spray width or pattern. Most pressure washers come with four universal nozzles and one soap nozzle.

Nozzle colors indicate different spray angles. For example:

Zero-degree nozzle: The red 0-degree nozzle creates high concentrated pressure to clean areas. It is mainly used for heavy-duty jobs like cleaning heavy build-up on concrete, sidewalks, and block paving or removing rust from equipment.

15-degree nozzle: The yellow 15-degree nozzle is used for intense moderate to heavy-duty cleaning like stripping paint from wood, metal or masonry, as well as removing oil, grease or mildew stains.

25-degree nozzle: The green 25-degree nozzle is used to tackle general light-duty tasks like washing off mud and dirt from driveways, patio furniture, decks, vehicles and more.

40-degree nozzle: The white 40-degree nozzle is often used for light-duty tasks like pressure washing more easily damaged surfaces like windows, cars, RVs and trucks.

65-degree nozzle: The black 65-degree nozzle produces the widest and gentlest spray patterns and is often used for applying detergent or rinsing soap.

Using the wrong nozzle or tip for your pressure washer could result in severe injury and costly property damage. Concrete damage is commonly caused by improper tip use, as are broken window seals and damaged wood and composite decks. To help reduce the risk of injury, experts caution against using the red, zero-degree nozzle or the zero-degree setting of an all-in-one adjustable nozzle. The higher-degree settings can get most jobs done without putting you at unnecessary risk.

After selecting the appropriate nozzle, ensure your pressure washer is properly connected to a water supply before turning on. Never keep your pressure washer running on idle for more than a few minutes. If you’re not going to be spraying, it’s best to turn off your pressure washer. Keeping a pressure washer running on bypass without spraying can damage the pump and internal control valves.

Frequently Asked Questions

Q: What is the difference between a pressure washer and a power washer?

A: The terms are often used interchangeably, but there is one main difference. Pressure washers use ground temperature water, whereas a power washer uses a heating element to heat the water before spraying it out. Due to the heating element, power washers are often more effective at removing stains with living bacteria, like mold.

Q: Do I need to wear protective gear when using a pressure washer?

A: Pressure washer nozzles can shoot water at 30 to 80 times more pressure than a standard garden hose and have surprisingly strong cutting capabilities, no matter which spray setting you use. According to Occupational Health and Safety magazine, water jetting hazards and injuries include noise, eye injuries, cuts, slips, trips, falls, head and water blasting injuries. Use caution and wear appropriate PPE, including safety glasses, head protection and cut-resistant gloves when operating a pressure washer. When the adjustable wand tip is set at its narrowest spray setting or tip, a jet of water could cause lacerations and other serious injuries.

Q: Can you run soap through a pressure washer?

A: When pressure washing alone isn’t enough to remove set-in stains, detergents can help remove tough dirt and spots. Detergents and soaps help loosen stains so your pressure washer can easily clean and help restore surfaces. There are specific pressure washer detergents depending on the type of job. Many pressure washers now feature detergent tanks making it easy to add soap to the basin of the pressure washer or the siphon hose. Never use detergents with bleach in your power washer because it could damage the pump, hose or nozzle. Pressure washer spray guns and wands like foamers and soap shooters attach to the end of your spray gun, allowing you to spray detergents or other chemicals without going through your pump.

Q: Can you damage hard surfaces like concrete with a pressure washer?

A: Yes. The main cause of accidental surface damage with pressure washers is using the wrong tip or nozzle. If you're unsure which nozzle to use, experts recommend starting with a wide spray tip and switching to one with a more direct angle as needed. The white 40-degree nozzle is an excellent general all-purpose tip to begin with.

Q: What OSHA standards apply to pressure washers?

A: According to OSHA, abrasive blasting uses compressed air or water to direct a high-powered stream of an abrasive material to clean and prepare an object or surface before painting or applying another type of coating. Pressure washer equipment can exceed 85 dBA, so it’s essential to always wear hearing protection as required by the OSHA Occupational Noise standard. Employers must also protect workers from hazardous dust levels and toxic metals that may come from a substrate and the blasted material or object. Depending on the job, appropriate PPE should be worn whenever pressure washing, including hearing protection, eye and face protection, a helmet, cut-resistant gloves that protect the entire forearm, aprons or coveralls, and safety shoes or boots.

The information contained in this article is intended for general information purposes only and is based on information available as of the initial date of publication. No representation is made that the information or references are complete or remain current. This article is not a substitute for review of current applicable government regulations, industry standards, or other standards specific to your business and/or activities and should not be construed as legal advice or opinion. Readers with specific questions should refer to the applicable standards or consult with an attorney.