Reasons why heater wire does not emit light like an electric lamp filament
Electric lamp filament is made of very thin and long tungsten metal. The resistivity of tungsten is very high. A lot of heat is generated in it due to the current flow. As a result, the filament glows white and emits light. But relatively thick nichrome wire is used in the heater.
As a result, the resistance of this wire is relatively low and the current does not cause the coil of nichrome wire to become white-hot like the filament of an electric lamp. Hence, the heater wire does not radiate light.