A thermal valve in a pressure washer prevents the pump from overheating by releasing hot water when it reaches a certain temperature.
Here's a breakdown of how it works, primarily in the context of a pressure washer, based on the available information:
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Normal Operation: While the trigger of the spray gun is engaged, water flows through the pump, preventing it from overheating.
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Stagnant Water Issue: When the trigger is released, water circulation stops. The pump continues to run, generating heat. If the water inside the pump remains stagnant, the temperature rises rapidly.
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Thermal Valve Activation: The thermal valve is designed to open automatically when the water temperature within the pump reaches a pre-set threshold (typically around 140-145°F or 60-63°C).
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Hot Water Release: Once the thermal valve opens, it releases the hot, stagnant water from the pump. This release allows cooler water to enter and circulate, preventing the pump from overheating and potentially causing damage to the seals and other components.
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Automatic Reset: Once the temperature drops below the threshold, the thermal valve automatically closes, allowing the pressure to build again when the spray gun trigger is engaged.
In essence, the thermal valve acts as a safety mechanism, protecting the pressure washer pump from damage caused by overheating when the unit is running but no water is flowing through the system.
