The thermal relief valve protects pressure washer pumps that operate in a safe temperature range to prevent overheating. The thermal relief valve keeps the pressure washer pumps operating in a safe range to prevent overheating (caused by water recirculation). At water temperatures above 145º F, packaging seals can fail. When the system is in bypass mode, the thermal relief valve opens to release hot water.
Cold water can then enter the pump to keep it running at a safe temperature. If the pump overheats, the thermal relief valves must be replaced. Think of this trapped pressure reliever as a relief valve. Depending on the type of discharge valve you have, it is activated by an increase in pressure or a decrease in flow.
When you release the trigger gun, the valve activates its spring and ball retention mechanism, causing water to pass through a bypass. The increase in pressure, without a relief valve to regulate it, could cause the water pressure to exceed the PSI limit and could damage the pressure washer pump. Remember to ensure that the unloading valve on your pressure washer is installed correctly and is compatible with your pressure washer. Secondly, the pressure washer's discharge valves allow you to easily adjust the water pressure while pressure washing with the machine.
Without a relief valve, water pressure continues to build up in the nozzle, which could cause a very unsafe situation. These pressure regulators depressurize water and send it to a bypass cycle so you can safely get away from the machine in case of emergency. It sends pressurized water to a bypass flowing from the outlet side of the pump to a water inlet or tank. While you'll want to check for other problems, such as blockages, troubleshooting your pressure washer may indicate that the unloading valve is the culprit.
This process depressurizes water and prevents pressure from building up while the pressure washer is idle. Without a pressure washer discharge valve, dangerous pressure can build up if you walk away to take a phone call, chase your dog, or chat with your neighbor. When you re-activate the pressure washer rod, the flow-operated unloader will turn off and redirect water to the nozzle. She has also worked as a commercial pressure washer in a processing plant for 3 years and has been using commercial and residential pressure washers for more than 15 years.