Fix Your Stuff Community Store

Free Shipping on Domestic Orders $75+

Prusa MK4 Print Fan Replacement

Introduction

Prusa MK4 comes with a print fan located on the right side of the Nextruder. It is essential for cooling freshly extruded plastic. However, if the fan is damaged (bearings failure, breaking of the fan blades), it can cause failed prints or severe stringing. This guide will show you how to safely open the Loveboard, unroute the delicate wiring, and swap in a fresh fan.

What you need

  1. Prusa MK4 Print Fan Replacement, Print Fan: step 1, image 1 of 3 Prusa MK4 Print Fan Replacement, Print Fan: step 1, image 2 of 3 Prusa MK4 Print Fan Replacement, Print Fan: step 1, image 3 of 3

    • Make sure the printer is turned off and the power cord is unplugged before you begin.

    • Move the extruder to the middle of the X and Y axes to ensure the workspace is clear.

    • Remove the Loveboard cover from the toolhead and set it aside.

    Edit

  2. Prusa MK4 Print Fan Replacement: step 2, image 1 of 2 Prusa MK4 Print Fan Replacement: step 2, image 2 of 2

    • Use tweezers to gently grip and disconnect the plastic body of the cooling fan connector from the Loveboard.

    • You can use your fingers as well; tweezers are just easier to use.

    • Pull only on the plastic connector body. Pulling directly on the wires can damage them or rip them out of the delicate crimp connector.

    Edit

  3. Prusa MK4 Print Fan Replacement: step 3, image 1 of 2 Prusa MK4 Print Fan Replacement: step 3, image 2 of 2

    • Use a 2.4mm hex key to unscrew the fasteners holding the print fan to the side of the extruder.

    Edit

  5. Prusa MK4 Print Fan Replacement: step 4, image 1 of 3 Prusa MK4 Print Fan Replacement: step 4, image 2 of 3 Prusa MK4 Print Fan Replacement: step 4, image 3 of 3

    • Pull the damaged fan free from the extruder body, and if needed make sure you clean the plastic waste on the shroud!

    Edit

  6. Prusa MK4 Print Fan Replacement: step 5, image 1 of 2 Prusa MK4 Print Fan Replacement: step 5, image 2 of 2

    • Route the replacement fan's cable neatly through the dedicated channel in the print fan holder.

    • The cable must not protrude out, otherwise the cooling fan will not be held into the holder properly.

    • Hold the new fan in place against the extruder body.

    Edit

  7. Prusa MK4 Print Fan Replacement: step 6, image 1 of 3 Prusa MK4 Print Fan Replacement: step 6, image 2 of 3 Prusa MK4 Print Fan Replacement: step 6, image 3 of 3

    • Using a 2.3mm hex insert and tighten the two long 2.5mm screws to secure the fan. Hold the fan tightly, if needed, to make sure there is no gap between the cooling fan and the shroud.

    • Tighten the screws gently to avoid cracking the plastic fan casing.

    • Verify that the screw ends are visible on the opposite side of the shroud to ensure the fan is secured with no gaps.

    Edit

  8. Prusa MK4 Print Fan Replacement: step 7, image 1 of 3 Prusa MK4 Print Fan Replacement: step 7, image 2 of 3 Prusa MK4 Print Fan Replacement: step 7, image 3 of 3

    • Gently snap the new cooling fan's connector into its dedicated port on the Loveboard.

    Edit

  9. Prusa MK4 Print Fan Replacement: step 8, image 1 of 1

    • Place the Loveboard cover back on.

    Edit
Conclusion

Once assembled, plug in the printer, turn it on and navigate to Control > Temperature > Print fan on the LCD screen to verify the new fan spins correctly.

One other person completed this guide.

Author

with 1 other contributor

Simranjit

Member since: 01/21/26

157 Reputation

1 Guide authored

Badges: 3

Team

York University, Team 4-10, Woodhouse Winter 2026 Member of York University, Team 4-10, Woodhouse Winter 2026

YORK-WOODHOUSE-W26S4G10

2 Members

1 Guide authored

0 Guide Comments

Add Comment

View Statistics:

Past 24 Hours: 0

Past 7 Days: 14

Past 30 Days: 14

All Time: 43