A thermal fuse is a safety device that interrupts an electrical circuit when the temperature reaches a predetermined level. Thermal fuses are commonly used in appliances, such as hair dryers, toasters, and coffee makers, to prevent fires in the event of overheating. Checking a thermal fuse is a simple process that can be done with a multimeter.
To check a thermal fuse, first set your multimeter to the ohms setting. Then, touch the probes of the multimeter to the terminals of the thermal fuse. If the thermal fuse is good, the multimeter will read zero ohms. If the thermal fuse is blown, the multimeter will read infinity ohms.