Description

Prusa Nextruder Heaterblock — OEM Replacement Heater Block

This is the OEM aluminium heater block for Prusa’s Nextruder hotend — the component that holds the heater cartridge, thermistor, and nozzle together and transfers heat to the melt zone. If your heater block is damaged, stripped, corroded, or has developed thermal issues from a crash or filament leak, this is the direct replacement.

Includes three M3x4 grub screws with Torx T6 drive for securing the heater cartridge and thermistor.

When to Replace the Heaterblock

Stripped or damaged threads from overtightening or repeated nozzle changes, filament leak that has solidified inside the block and can’t be cleaned, physical damage from a print head crash or collision, corrosion or pitting affecting thermal contact with the heater and thermistor, and as part of a complete hotend rebuild when restoring the Nextruder to factory condition.

In most cases, temperature errors and thermal issues are caused by the heater cartridge or thermistor rather than the block itself. Replace the heaterblock only when the block is physically damaged or contaminated.

Torx T6 Grub Screws — Not Hex

The included M3x4 grub screws use a Torx T6 drive, not hex. You’ll need a Torx T6 driver or bit to install them. Using a hex key will strip the screw heads.

What’s Included

Nextruder heaterblock × 1 (aluminium)
M3x4 grub screws × 3 (Torx T6)

Not included: nozzle, heater cartridge, thermistor, or silicone sock. These are separate parts — if you need a complete assembled hotend, see our Prusa Nextruder Hotend listings.

Compatibility

Prusa MK3.9 / MK3.9S
Prusa MK4 / MK4S
Prusa XL
Prusa CORE One / CORE One+
Prusa CORE One L

Not compatible with the MK3/MK3S/MK3S+ (which use E3D V6 heater blocks), Prusa MINI/MINI+, or any non-Nextruder printer.

Installation

Refer to the Prusa Knowledge Base repair manual for your specific printer model at help.prusa3d.com. The heaterblock is assembled with the nozzle, heater cartridge, and thermistor — ensure correct torque on the grub screws and nozzle to prevent filament leaks.