kenwood dishwasher

hi all

have just been out to a kenwood intergrated dishwasher model KDW243A
serial 623sn 002011 the fault code was f 3 so checked out the thermostat nearest the heater to find it faulty. my question, is this a protection stat and do i need to replace any other thermostats at the same time. the thermostast has KSD201 also a red spot on it and the numbers 90/-35 on it.