Thermal Fuse
A one-time-use safety device that opens permanently if an appliance overheats.
Definition
A thermal fuse is a one-time-use safety device that opens (breaks circuit) permanently if the appliance temperature exceeds a preset limit. Once open, the appliance loses power to its heating element (dryer) or main circuits (some dishwashers, microwaves) until the fuse is replaced. Thermal fuses are inexpensive ($5-$15) and field-replaceable, but always determine why the fuse blew before replacing — a blown fuse usually indicates a restricted vent (dryer) or a stuck thermostat (other appliances) that will blow the new fuse if not corrected.
Where this term appears
Thermal Fuse comes up in product spec sheets, service reports, and troubleshooting documentation across most major appliance brands. If you encountered it in a manual or a service description and want context for how it fits into the larger picture, the related articles in the sidebar drill into the practical details. The glossary as a whole is intended as a quick lookup reference; for a deep dive on any specific topic, jump to the related buying guide or troubleshooting article.