Heater Block Assembly PT100 RTD Sensor Replacement

Model [X] AON-M2 [X] AON-M2 2020
Category [ ] Preventive [X ] Corrective [ ] Troubleshooting


The procedure that follows explains how to replace the PT100 resistance temperature detector (RTD) sensor.

Estimated time: 30 minutes


Qty Description Specification
1 Wrench 7 mm, open
1 Wire Brush Clean, Soft bristle
A/R Rags Lint-free
A/R Isopropyl Alcohol 99%

Parts Information

Qty Part Number Description
2 EL-RTD-R02 PT100 RTD Sensor

Personal Protective Equipment

Qty Description Specification
1 Safety Eyewear N/A
A/R Gloves Nitrile

Prepare the Machine

  1. Home XYZ.
  2. Lower the Z-axis by 300 mm.
  3. Push the E-stop button.
  4. Wait until the build chamber, build plate and hot ends are at room temperature.

Remove the Heater Block Assembly

Allow all machine components to reach room temperature prior to proceeding further. Failure to allow components to cool down will result in thermal injury (burns) to personnel.

  1. Remove the heater block assembly. Refer to Heater Block Assembly Replacement.

Replace the PT100 RTD Sensor

Heater Block Assembly RTD Sensor Replacement

  1. Remove all contaminant buildup from the PT100 RTD Sensor head with the soft bristle wire brush.
  2. Clean any residue from the PT100 RTD Sensor head with a clean lint-free rag.
  3. Remove the PT100 RTD Sensor using the 7 mm wrench. Discard PT100 RTD Sensor.
  4. Clean the surface of the heater block to remove contaminant buildup.
  5. Install the new RTD sensor into the HBA and hand-tighten.

    Do not over-tighten the PT100 RTD Sensor into the HBA. Over-tightening the PT100 RTD Sensor will cause permanent damage to the PT100 RTD Sensor.

  6. Carefully tighten the PT100 RTD Sensor using the 7 mm wrench until it cannot be removed by hand.


  1. Install the HBA. Refer to Heater Block Assembly Replacement.
  2. Tap on the Temp tab on the left-hand side of the screen.
  3. Test the PT100 RTD Sensor to make sure that the current temperature values shown for Left Tool T0 and Right Tool T1 are valid and the values show room temperature. Refer to Test Hot End PT100 RTD Sensor

Last modified: June 14, 2021