Technical Information
Troubleshooting Guides
Our technical guides are available online to help you determine your problems.
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PSI vs. GPM
From Alkota's ultimate guide to help you purchase the right pressure washer.
What's most important: HP, PSI or GPM?
First of all, it's important to understand what each of these acronyms mean. HP stands for horsepower, PSI for pounds per square inch and GPM for gallons per minute. The HP of a pressure washer is divided up to produce both the pressure at which the water is released (PSI) and the number of gallons that are released (GPM). For example, a 2 HP motor can produce 2.1 GPM at 1600 PSI or it can produce 3.0 GPM at 1100 PSI. Cleaning power is a function of both volume and pressure.
Size does matter.
When selecting a pressure washer, first determine the minimum PSI you need to break the bond between the dirt and the surface you are cleaning. "Units of cleaning power" can be calculated by multiplying the GPM by the PSI. (i.e., 4GPM x 1800PSI = 7,200 units of cleaning power)
After selecting a pressure washer with at least the desired PSI level, look at the GPM rate. The higher the GPM, the faster your cleaning job will be. That's because once you have the necessary pressure to remove the dirt and grime, the only way to make your job faster is to increase the rate at which water is released.
You can lower the cleaning pressure capacity of a larger washer by simply changing spray nozzles or using a variable pressure wand. You can not make a smaller washer bigger. Horsepower is horsepower,; a 2 HP motor can not pump over its capacity.
Always buy a unit big enough for your needs. Buying a unit that does not have adequate cleaning power will cost you extra clean-up time and repairs in the future.
Nozzle Size Chart
Improper nozzle size can cause your pressure washer to operate ineffectively.
The orifice size of the nozzle determines the operating pressure of your pressure washer. The smaller the orifice, the greater the restriction of water flowing through the pressure washer.
- Using a nozzle with too large an orifice will decrease your pressure.
- Using a nozzle with too small an orifice will limit water flow causing your pump to overload and damage the machine.*
*Unless machine is capable of running at higher pressures. Consult Citation before attempting to increase pressure with a smaller nozzle.
The link below will help you determine the proper size nozzle based on your GPM (Gallons Per Minute) and PSI (Pressure Per Square Inch).
View Nozzle Chart
Nozzle Degrees
Nozzles come in varying degree patterns. Quick couple nozzle degrees are color-coded as follows:
- Black-Soap nozzle. It activates injector for soap application.
- Red-0 degree pattern, straight shot for removing paint, etc.
- Yellow-15 degree pattern. Best for cars, trucks, decks, houses and concrete, etc.
- Green-25 degree pattern. Can also be used on cars, trucks, decks, houses, concrete, etc.
- White-40 degree pattern. Widest fan available. Best for covering a large surface or moving a lot of dirt, etc.
If you are unsure, the nozzle orifice size and degree are stamped into the side of the nozzle. (QCMEG2505=Quick Couple Nozzle, 25 degree with #5 orifice)
Threaded nozzle degrees are harder to come by. The nozzle degree and orifice size are stamped into the side or top of the nozzle (1/8 MEG 15055=1/8 Threaded Nozzle, 15 degree with #5.5 orifice.)
Still need help?
Call Citation, The Pressure Washer Store, that is why we are here!
Time Delay Shutdown
Time Delay Shutdown is available for our pressure washers. It can be installed on your machine when ordered or we can install the system in the field.
Time Delay Shutdown can be set up to shutdown your pressure washer completely to prevent premature failure of the packing in your pump. This is valuable if your operator is away from the pressure washer (i.e. in another room or area using the trigger gun) in order to avoid costly repairs.
Letting the pressure washer run without squeezing the trigger can cause the pump to heat up and damage the pump, packing, and or pistons in the pump.
Remote Control
Citation can set up a remote for your system to avoid running back to the on/off switch on your machine.
In order to set up a remote we need to know the make and model of your machine. This remote can be added at the time of purchase and in some cases can be installed in the field.
Freezing Prevention
View our guide for protecting your pressure washer from freezing.