I'm repairing a heater that someone threw in the trash (this model):
It has an internal thermostat next to the heating wires, plus a thermal fuse.
What is the reason for a fuse in addition to the thermostat? It seems to me that the thermostat alone is sufficient protection against overheating, since the fan does not produce heat.
Best Answer
The fan doesn't produce heat, but if the fan never blows, the heating element might overheat and start a fire.
Thermostats fail. Safety regulations generally work on a "single fault" principle. Meaning no single fault in a product should lead to a safety hazard. In this case, the thermal fuse provides a backup to prevent a fire in case the thermostat fails (or, as @winny points out, in case the fan is mechanically blocked).