150°C Resettable Thermostat (M4 Threaded Stud) Resettable high-limit safety thermostat that trips at 150°C, mounted via an M4 threaded stud. Found in some Fiorenzato C.S. (espresso machine) and Lavazza models. SPECIFICATIONS Trip point 150°C; M4 threaded stud mount; manually resettable (not a one-time thermal fuse) COMPATIBILITY Fits: some Fiorenzato C.S. and Lavazza models - verify against your machine's wiring diagram before ordering INSTALLATION Technician recommended - this is part of the boiler's safety circuit. PRO TIPS Because it's resettable rather than a one-shot fuse, a tripped thermostat can often be reset once the boiler cools instead of replaced outright. But repeated tripping points to a failing high-limit control or scale buildup insulating the boiler wall - not a bad thermostat.