The Dryer Thermal Fuse (Thermal Cutoff, Temperature Fuse) is a 2 by inch, white, plastic safety mechanism that stops the flow of electricity to the motor circuit when a dryer overheats. If the fuse is missing or broken, your dryer will not start. A thermal fuse fails when the exhaust temperature exceeds the fuse rating, that is when the temperature rises above the temperature that the fuse is designed to handle. This can occur when a heating element is shorted, a regulating thermostat or thermister fails, or with a partially restricted exhaust vent. The fuse attaches to the blower wheel housing. It must be replaced when there is no longer continuity between the terminals. This is a one-time fuse, meaning it cannot be re-set. The replacement part features two 3/16 inch terminals.