The Karcher 4.580-359.0 Thermo Valve 60 GRD helps regulate temperature for safe and reliable pressure washer operation. Designed as a replacement thermal valve, it monitors water temperature within the pump and releases overheated water when necessary, allowing cooler water to enter the system. This process helps protect the pump from excessive heat buildup during bypass operation and... https://www.wholetoolbox.com/karcher-4-580-359-0-thermo-valve-60-grd/4.580-359.0.html