COOL DOWN YOUR COIL
Never shut down a hot water pressure washer without properly cooling down the heating coil. Overheating and damage to the pump components, hoses and O-rings will occur without first cooling the pressure washer.
Hot water pressure washers provide many benefits for your facilities cleaning applications. The hot water produced by a pressure washer provides much quicker cleaning results, reduces labor time spent cleaning and is a must when dealing with the removal of oils and grease. The heat left unchecked, however, can also destroy the very equipment you rely on.
Damage to the pressure washer will occur when the pressure washer has not been adequately cooled down. You should never shut down a hot water pressure washer without properly cooling down the heating coil.
As the pressure washer is used, pressurized water is sent from the pump to the heating coil. Water travels through a coiled steel pipe as the burner is producing heat and sending heat through the center of the coil. As the water exits the heating coil, a thermostat monitors the outgoing temperature and cycles the burner on as required to maintain the set temperature. Typically heated water will reach a maximum temperature of 160 to 190° F. This constant temperature will be maintained based on the consistent flow of water from the pump. Once the burner is shut off, the flow of cold water to the heating coil serves to cool down the coil to ambient temperature. It will generally take 2-3 minutes of running the unit without heat to cool down the coil. A good rule of thumb is to turn the burner off and run the unit with the burner off until the wand is cool to touch. This insures the coil is cooled before the unit is shut down.
A common theme in pressure washers with a high failure rate is the operators shutting down the unit without proper cooling. The potential for failure is very high. Remember, the coil is red hot during burn conditions. If allowed to shut down without cooling, you have the heat of the coil itself heating the water remaining in the coil. This water can easily reach temperatures exceeding 200° F. As this water heats, the heat is thermally transferred through the water directly to the pump. This elevated temperature in the pump will lead to damaged seals, leaking seals, and eventually loss of pressure and a leaking pump. If the oil seals are impacted, water can enter the crankcase and lead to catastrophic pump failure. In addition, hot water left in the high pressure hose, bypass hose, and trigger gun can lead to softening of the hoses and o-rings and will dramatically reduce the life of the hoses, quick connects, and trigger guns.
Insuring longevity and reliability of your hot water pressure washer is as easy as cooling down the unit before shutting it off. To avoid costly failures, employees should be trained to begin the shut down process by turning off the burner and depressing the trigger gun for 2-3 minutes until enough cold water runs through the wand to make it cool to th