Heat Zone Length
====
This setting measures the distance between the tip of the nozzle and the point along the filament where the filament starts getting heated.

The heat zone essentially determines the "danger zone" for the filament to be positioned during the print. While the nozzle is hot and the filament is within this heat zone, the filament will get molten and so it could degrade. This measurement is therefore a good starting point for long term retractions, such as the [Nozzle Switch Retraction Distance](../dual/switch_extruder_retraction_amount.md) or the [Filament Park Distance](machine_filament_park_distance.md). Some profiles have retraction lengths depend on the heat zone length.

**Since this is a machine setting, this setting is not normally visible in the settings list.**