A Hot Pressure Washer Explained: Inside and Out
A hot pressure washer is very useful for cleaning dirt and grease from a variety of surfaces. These washers come in all sizes from small household units to large fixed mount systems that are used for volume washing, such as on a new car lot. Hot pressure washers differ from steam cleaners because the pressurized water will not turn to steam even at 212 degrees. Hot pressure washers work by using water heated to 200 degrees Fahrenheit and a pump which forces the water through a constrictor nozzle. Depending on the model and manufacturer of the pressure washer equipment, you can get a washer that will automatically start and stop. Another feature that is optional on some models is timed shut down delay using a relay that shuts the unit down after a certain interval of usage.
The common types of hot water pressure washers generate hot water using diesel, propane, kerosene or natural gas. These heaters generally have the capacity to provide 4 or more hours of continuous washing. The heating units on these hot pressure washers typically have the capability to raise the incoming water from a hose between 130 and 150 degrees as is comes into the heat chamber. When you add that figure to the ambient temperature of the water, the washer can deliver water at 180 to 200 degrees at the nozzle. The heat chamber on a well tuned washer will run continuously as long as water is flowing though the heating chamber. Once the water flow is removed, the burner will shut off automatically. The burner can be automatically shut off through the use of a flow control switch. This switch can be a flow control switch, a pressure switch or a vacuum switch acting on the fuel solenoid.
The pressure washer works by using an electric pump to continuously circulate water in the system. As the trigger on the pressure washer wand is pulled, the water bypass valve closes and forces the water through the wand and out of the constriction nozzle at the end of the wand. The pump itself does not provide the high pressure water, but rather it's the restriction of the wand/nozzle combination that creates the forceful stream of water. At the time the trigger is pulled, the heating unit will cycle on to heat the water as it is propelled out of the nozzle. It is important to note, that the hot pressure washer should not run for more than 5 minutes without the trigger on the wand being pulled. The pressure washer produces water pressure between 1000 psi and 5000 psi. The variation in pressure is based on the nozzle selected for the end of the wand and there are charts available to select the proper nozzle. The nozzles are sized by diameter in fractions of an inch. The chart will typically cross reference the diameter to the pressure and application. You should select a lower pressure nozzle to use with soap and a higher pressure nozzle to take off tough grease.
A hot water pressure washer is a useful tool for tough cleaning jobs, from the siding on a home to a greasy garage floor.