Skip to main content
  1. This guide will take you through the replacement of the heatsink, heatbreak and heaterblock.
    • This guide will take you through the replacement of the heatsink, heatbreak and heaterblock.

    • All necessary parts are available in our eshop shop.prusa3d.com

    • NOTE: Read the instructions carefully. Some steps may vary depending on the type of replacement part.

  2. To replace hotend parts, please prepare: Needle-nose pliers for zip ties (1x) Wrench size 17 EU / 32" US (1x)
    • To replace hotend parts, please prepare:

    • Needle-nose pliers for zip ties (1x)

    • Wrench size 17 EU / 32" US (1x)

    • Allen keys - 2.5/2.0/1.5 mm (1x)

    • Torque wrench (1x)

    • Standard Socket size 7mm EU / 1/4" US (1x)

    • Cloth or piece of fabric 15x15cm (2x)

    • The torque wrench has to be set to values around 2-3 Nm and is critical for the proper tightening of the nozzle. You can use a regular wrench, but there is a risk of damaging the hotend.

  3. Make sure that:
    • Make sure that:

    • The filament is unloaded from the hotend (remove also the spool and the spool holder).

    • X-axis with the extruder is slightly above the middle of the height (Z-axis) of the printer.

    • CAUTION: In some steps, you will need to preheat the printer. Avoid touching the HOT parts!

  4. In this guide, we won't disassemble the extruder completely. Thanks to the new design, it is enough to release the screws and move the plastic parts slightly apart. Release and remove the M3x14 screw from the hotend fan. Release and remove the M3x20 (M3x18) screw from the hotend fan. Note that the fan-shroud might fall off.
    • In this guide, we won't disassemble the extruder completely. Thanks to the new design, it is enough to release the screws and move the plastic parts slightly apart.

    • Release and remove the M3x14 screw from the hotend fan.

    • Release and remove the M3x20 (M3x18) screw from the hotend fan. Note that the fan-shroud might fall off.

    • Leave the other two screws holding the hotend fan in place. No need to remove them.

    • Release and remove both screws and remove the Front print fan.

    • Carefully insert the Front print fan in the X-axis belt.

  5. WARNING: This and the next step are not intended for the HEATSINK replacement!  Skip to Protecting the heatbed On the printer's screen navigate to the Settings. Open the Temperature menu.
    • WARNING: This and the next step are not intended for the HEATSINK replacement! Skip to Protecting the heatbed

    • On the printer's screen navigate to the Settings.

    • Open the Temperature menu.

    • Set the nozzle temperature to 250 °C by turning the knob.

  6. WARNING: Avoid touching the HOT nozzle!!! Set the torque wrench to 3 Nm (26.5 in-lb). With one hand, hold the heaterblock using the wrench size 17 (32"). Place the wrench under the cables to avoid damage.
    • WARNING: Avoid touching the HOT nozzle!!!

    • Set the torque wrench to 3 Nm (26.5 in-lb).

    • With one hand, hold the heaterblock using the wrench size 17 (32"). Place the wrench under the cables to avoid damage.

    • With the other hand, use a torque wrench, place it on the nozzle and slightly loosen it. Do not remove the nozzle at the moment.

    • Navigate to the Preheat menu and at the end of the menu select Cooldown.

    • Wait for 15 - 20 minutes to ensure the hotend is cooled down completely before proceeding to the next step.

  7. Turn the printer off and unplug it!
    • Turn the printer off and unplug it!

    • Before these steps, it is recommended to protect the heatbed!

    • Use any cloth or piece of fabric, which is thick enough and cover the heatbed. This will ensure you won't damage (scratch) the surface during the disassembly.

  8. In this guide, we won't disassemble the extruder completely. Thanks to the new design it is enough to release the screws and move the plastic parts slightly apart. Release both screws, but don't remove them. We will use them to hold the extruder parts together.
    • In this guide, we won't disassemble the extruder completely. Thanks to the new design it is enough to release the screws and move the plastic parts slightly apart.

    • Release both screws, but don't remove them. We will use them to hold the extruder parts together.

    • Release both screws, but don't remove them. Just make sure they won't block the motor from moving.

  9. Before you move any parts, make sure there is enough slack in the extruder motor cable!!! If not, you have to cut the zip ties on the textile sleeve, open the box with electronics and make sure the motor cable is free to move. Carefully move the extruder apart. First, pull the motor, then the lower part with the print fan.
    • Before you move any parts, make sure there is enough slack in the extruder motor cable!!!

    • If not, you have to cut the zip ties on the textile sleeve, open the box with electronics and make sure the motor cable is free to move.

    • Carefully move the extruder apart. First, pull the motor, then the lower part with the print fan.

    • Create a gap similar to the picture. Align the printed part holding the motor with the edge of the fan frame.

    • Reach for the hotend and incline its upper part towards the motor, it should slide out.

    • If the hotend is still stuck inside, release the screws more and extend the gap between the printed parts.

    • BE EXTRA CAUTIOUS with the hotend cables!!! You can break them! Use a small force to pull the hotend out. Don't bend the cables.

  10. Choose the guide for the part you need to replace: Heatbreak replacement Heatsink replacement
  11. For the following steps, please prepare: New heatbreak (1x)
    • For the following steps, please prepare:

    • New heatbreak (1x)

    • Thermal paste (1x)

  12. Before you continue with this step, make sure the nozzle is loose. Hold the heaterblock with one hand and start screwing the heatsink with the heatbreak out.
    • Before you continue with this step, make sure the nozzle is loose.

    • Hold the heaterblock with one hand and start screwing the heatsink with the heatbreak out.

    • With the heatbreak out, press the black plastic collet down to release the PTFE tube.

    • Pull out the PTFE tube from the heatsink.

  13. Use the second cloth to protect the thread of the heatbreak.
    • Use the second cloth to protect the thread of the heatbreak.

    • Hold the heatsink and using pliers release and remove the heatbreak.

    • We are done with removing the old heatbreak, let's move to the next step and install a new one ;)

  14. Take the new heatbreak and apply most of the content of the thermal paste package on the long thread. Spread it evenly with a paper towel. Do not apply the paste on the short thread!: Incorrect application: the thermal paste is covering both threads of the heatbreak.
    • Take the new heatbreak and apply most of the content of the thermal paste package on the long thread. Spread it evenly with a paper towel.

    • Do not apply the paste on the short thread!:

    • Incorrect application: the thermal paste is covering both threads of the heatbreak.

    • Correct application: the thermal paste is covering on the long thread of the heatbreak.

    • Applying the paste on the short thread can later lead to a gap between the heatbreak and the nozzle. The nozzle might then become clogged when the filament is loaded.

  15. Screw the long thread of the heatbreak (with the paste) into the heatsink. Ensure the entire thread is screwed in. After you screw the heatbreak in, clean the excess paste on the surface of the heatsink. To finish the replacement process jump to Assembling the PTFE tube
    • Screw the long thread of the heatbreak (with the paste) into the heatsink. Ensure the entire thread is screwed in.

    • After you screw the heatbreak in, clean the excess paste on the surface of the heatsink.

    • To finish the replacement process jump to Assembling the PTFE tube

  16. For the following steps, please prepare: New heatsink (1x)
    • For the following steps, please prepare:

    • New heatsink (1x)

    • Thermal paste (1x)

    • The heatsink includes a new black plastic collet, don't use the old one.

  17. Press the black plastic collet down to release the PTFE tube.
    • Press the black plastic collet down to release the PTFE tube.

    • Pull out the PTFE tube from the heatsink.

  18. Hold the heaterblock with one hand and start screwing the heatsink out. Avoid loosening the heatbreak from the heaterblock! To hold the heaterblock firmly we recommend using the wrench size 17 (32")   Keep the wrench away from the cables to avoid damage.
    • Hold the heaterblock with one hand and start screwing the heatsink out.

    • Avoid loosening the heatbreak from the heaterblock!

    • To hold the heaterblock firmly we recommend using the wrench size 17 (32") Keep the wrench away from the cables to avoid damage.

    • We are done with removing the old heatsink, let's move to the next step and install a new one ;)

  19. Before we install the new heatsink, clean the old thermal paste from the heatbreak.
    • Before we install the new heatsink, clean the old thermal paste from the heatbreak.

    • Apply most of the content of the thermal paste package on the longer heatbreak thread. Spread it evenly with a paper towel.

  20. Screw the new heatsink on the heatbreak. Make sure the heatbreak is all the way in the heatsink. After you screw the heatbreak in, clean the excess paste on the surface of the heatsink.
    • Screw the new heatsink on the heatbreak. Make sure the heatbreak is all the way in the heatsink.

    • After you screw the heatbreak in, clean the excess paste on the surface of the heatsink.

    • To finish the replacement process jump to Assembling the PTFE tube

  21. For the following steps, please prepare:
    • For the following steps, please prepare:

    • New heaterblock (1x)

  22. WARNING: Do not pull the thermistor or heater cables. Follow the instructions!
    • WARNING: Do not pull the thermistor or heater cables. Follow the instructions!

    • Release the thermistor screw and using the Allen key gently push the thermistor out.

    • Release the heater screw and using the Allen key gently push the heater out.

  23. Remove the nozzle from the heaterblock and keep it for later use.
    • Remove the nozzle from the heaterblock and keep it for later use.

    • Hold the heaterblock with one hand and start screwing the heatsink out.

    • We are done with removing the old heaterblock, let's move to the next step and install a new one ;)

  24. Insert the thermistor to the new heaterblock and secure by tightening the lock screw.
    • Insert the thermistor to the new heaterblock and secure by tightening the lock screw.

    • Then insert the heater to the heaterblock and secure it by tightening the black screw. Make sure the heater hangs over on the right side, see the picture.

  25. Screw the nozzle slightly in the heaterblock. Create a gap about 0,5 mm (0.02 inch), see the picture. Secure the nozzle against movement with one hand.
    • Screw the nozzle slightly in the heaterblock. Create a gap about 0,5 mm (0.02 inch), see the picture.

    • Secure the nozzle against movement with one hand.

    • With the other hand, screw the heatbreak with heatsink into the heaterblock from the opposite side until it touches the nozzle inside. Do not tighten anything by torque wrench at the moment.

  26. Now it is time to insert the PTFE tube back in. Note, that each end of the tube is different: One end of the tube has "rounded" outer edge. This end must be inside the hotend. Look at the other end, where the tube is drilled inside, the shape of the edge is "conical". This is the side, where filament enters the tube. This part must be outside the hotend.
    • Now it is time to insert the PTFE tube back in. Note, that each end of the tube is different:

    • One end of the tube has "rounded" outer edge. This end must be inside the hotend.

    • Look at the other end, where the tube is drilled inside, the shape of the edge is "conical". This is the side, where filament enters the tube. This part must be outside the hotend.

    • Push the black collet in. Slide the tube all the way in and hold it!

    • Using the other hand pull the collet out and only then release the tube!!! THIS IS CRUCIAL for the hotend to work properly.

  27. Place the hotend back inside the extruder. Ensure the orientation is the same as in the picture with cables on the left side. IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture! IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture!
    • Place the hotend back inside the extruder. Ensure the orientation is the same as in the picture with cables on the left side.

    • IT IS CRUCIAL to ensure the hotend fits to the extruder-body!!! The printed part is shaped according to the hotend. See the second and the third picture!

  28. WARNING: This step is not intended for the HEATSINK replacement!  Skip to the next step. Plug the printer in, turn it on and preheat the nozzle to 250 °C.
    • WARNING: This step is not intended for the HEATSINK replacement! Skip to the next step.

    • Plug the printer in, turn it on and preheat the nozzle to 250 °C.

    • WARNING: Avoid touching the HOT nozzle!!!

    • Set the torque wrench to 2.5Nm (22 in-lb).

    • With one hand, hold the heaterblock using the wrench size 17 (32"). Place the wrench under the cables to avoid damage.

    • With the other hand, use a torque wrench, place it on the nozzle and tighten it.

    • Navigate to the Preheat menu and at the end of the menu select Cooldown.

    • Wait for 15 - 20 minutes to ensure the hotend is cooled down completely before proceeding to the next step.

  29. Carefully and slowly push all the parts together. In case of any significant resistance, STOP immediately and check, which part is blocking the movement. Check once again the correct position of the hotend. Look from below the extruder. The heater block should be oriented as shown in the picture.
    • Carefully and slowly push all the parts together. In case of any significant resistance, STOP immediately and check, which part is blocking the movement.

    • Check once again the correct position of the hotend. Look from below the extruder. The heater block should be oriented as shown in the picture.

  30. Tighten both screws, but ensure no cable is pinched on both sides of the extruder. Repeat the same approach on the front side. Tighten both screws. Ensure no cable is pinched.
    • Tighten both screws, but ensure no cable is pinched on both sides of the extruder.

    • Repeat the same approach on the front side. Tighten both screws. Ensure no cable is pinched.

  31. Fix the fan in place using two M3x20 screws. Tighten both screws just slightly, we need to adjust other parts before fully tightening them. Use the M3x14 screw to fix the fan in place. Don't overtighten it, you can break the fan's plastic casing. Place fan-shroud back in the extruder. Fix it in place with the M3x20 (M3x18)  screw.
    • Fix the fan in place using two M3x20 screws. Tighten both screws just slightly, we need to adjust other parts before fully tightening them.

    • Use the M3x14 screw to fix the fan in place. Don't overtighten it, you can break the fan's plastic casing.

    • Place fan-shroud back in the extruder. Fix it in place with the M3x20 (M3x18) screw.

    • Once all parts are seated, tighten both screws on the front Print fan, but be careful, you can break the plastic casing.

  32. Take a look from the side of the extruder. The nozzle should be slightly below the printed fan-shroud.
    • Take a look from the side of the extruder. The nozzle should be slightly below the printed fan-shroud.

    • The flat part of the fan shroud has to be parallel to the heatbed surface.

  33. Great job! Heat the printer up and try it out ;)
    • Great job!

    • Heat the printer up and try it out ;)

Finish Line

One other person completed this guide.

Jakub Dolezal

Member since: 02/20/2017

223 Guides authored

Team

Prusa Research Member of Prusa Research

Community

3 Members

365 Guides authored

0 Comments

Add Comment

View Statistics:

Past 24 Hours: 25

Past 7 Days: 143

Past 30 Days: 832

All Time: 961