Tip: Partly unscrew the front left thumb screw in the print head to better reach the hot end isolator.
- Loosen the nozzle from the hot end isolator (the metal ring with the holes in it) by inserting one of the hex keys that came with your Ultimaker into one of the holes of the hot end isolator and turning it counter-clockwise
- If the hot end isolator will not turn there is plastic in the threads, which locks the isolator in place. Go to Maintenance > Advanced > Heat-up Nozzle > and set it to 100 degrees to soften the plastic. The isolator will rotate easily now
- Once the isolator is loose enough the nozzle will drop down. If the nozzle was heated up be careful when handling it. Turn the Ultimaker off before continuing with the next step
- Use a hex key to loosen the set screw that is attached to the top of the heater block. Once this screw is loosened carefully pull out the PT100 B sensor* and heater cartridge. If the nozzle was heated up be careful when handling the heater
Caution: Do not pull at the PT100 B sensor with much force, as it can break. Take the PT100 B sensor cable out slowly, with a twisting motion. Apply sewing machine oil or WD40 to the heater block if it feels stuck. If the PT100 B sensor does break, replace it with a spare.