Print Head

This replacement applies to Ultimaker S5 and Ultimaker S3 printers. To replace the white plastic printhead, please see the instructions immediately below. To replace other parts:

• the hot end cooling fan (front fan) see these instructions here (instructions here are for the UM3, process is the same)
• the model cooling fans (side fans) see these instructions here (instructions here are for the UM3, process is the same)
• the printhead PCB, please see here 
• the nozzle cover, please see here

Printhead

1. Remove filament from printer. Go to Material --> Print Core 1 and/or Print Core 2, and choose to unload the material in the unloading wizard. Wipe the nozzle tips clean with a paper towel while they are still hot, then, power off the printer.

2. Slide the white, horseshoe shaped clamp clips sideways out of each of the white collets in turn.

3. Push down on the white collets while pulling up on the bowden tubes to free them from the printhead. Note: if the filament could not be ejected from the printhead, you can still remove the bowden tube, and cut the filament off above the collet.

4.Using your 2mm hex head screw driver, unscrew the 2 long screws at the rear of the printhead, highlighted in green below. Then, remove the small back cover on top of the printhead. Lift the cover vertically up to slide it off.

5. Press your screwdriver against the plastic flap on the front of the connector to release the printhead cable from the printhead.

Here's a clearer view of the cable and connector:

6. You will need to push/tilt the black plastic blocks that hold the print head shafts in place in order to remove the printhead shafts. For S5 customers: start with the printhead to the left or right of center; you don't want your printhead shaft to catch on the magnet that holds your doors.

I recommend tilting the front and back blocks first and sliding the Y printhead shaft out forward through the front of the machine.

This should make it easier to then tilt the left and right blocks to remove the X printhead shaft. Once it's free of the blocks, just turn it slightly diagonal to be able to pull the X printhead shaft and printhead out of the top of the printer. While working, take care. Even a short drop can damage the tip of your Print Core. 

7. To replace the printhead back inside the printer, the longer print head shaft should go through the bearing running left to right, and the shorter one, front to back. 

Slide the long printhead shaft through the printhead on the left to right axis and turn the printhead and shaft slightly diagonally to bring it back into the printer--rest the printhead shaft on the U shaped opening at the top of your sliding blocks. The shafts fit into the black blocks as a push fit and may require a little force. When you push them into position, make sure to hold the sliding block straight; tilted blocks will cause problems with your active leveling or may not stay seated during printing.

Once the X printhead shaft is seated, tilt your printhead slightly so you can slide the Y printhead shaft between the belts at the front of your printer, and skewer it through the printhead. Seat it firmly in the front and back blocks, making sure they are perpendicular and not tilted. 

8. Press the printhead cable into the connection port on the printhead and make sure you hear it click into place, to let you know it's fully seated.

9. Press the top-rear plastic piece back into position and screw the printhead screws back in place. If possible, apply a little removable thread-locker to the ends of the screws before screwing them in. When tightening the screws, make sure that all parts of the printhead block are well aligned.

10. Push both of your bowden tubes back into their respective positions on the printhead as far as they will go. Then, raise the collets to slip the horse-shoe shaped clip in place under the collet. This clip is vital for helping your bowden tube remain seated securely during printing.

12. After you have installed your printhead, perform the lift switch calibration. If your printhead or print cores are new, run an XY offset calibration. This can be accessed in the menu by System --> Maintenance --> Calibration --> XY Offset Calibration. 

Nozzle Cover

Printhead PCB

(At this time the available video shows the Ultimaker 3 printhead; the process is nearly identical except that your printhead cable connects on the back of your PCB board instead of the front.)