Thermal Runaway Error

Overview

If the Viki displays the error message “Thermal Runaway,” this indicates the set point and actual temperature are more than 10°C different for more than 60 seconds.

Tools Needed: 

• Multimeter 

Before proceeding, please collect and record the following data: 

• Photos of your hot ends with the fans removed (front and bottom view) 
• Gigabot Number
• Screenshot of temperature graph when error occurs (instructions below)
• .factory file
• Nozzle size
• Print speed
• Part cooling fan on?
• Did thermal runaway error happen:
  • While heating the bed?
  • While heating the hot end? 
  • After the first layer when the outrigger fan turns on?

Initial checks: 

1. Firmware temperature setpoint bug
   If the printer is running firmware version 4.1.3 or 4.1.5, there is a known issue where the heated bed may stop increasing in temperature if the setpoint is raised after the bed has already reached its initial target.

   • Example:
     The bed is set to 60°C and successfully reaches that temperature. The setpoint is then increased to 100°C, but the bed stalls around 68°C and fails to continue heating.

   • Solution:
     Power-cycle the Gigabot, then set the bed temperature directly to the desired value (e.g., 100°C) after reboot.

2. Hot end temperature instability:
   If the hot end temperature fluctuates by more than ±3°C during heating or printing, this typically indicates a failing or damaged thermocouple. 

   • Solution:
     Replace the Hot End Thermocouple.

Verify: 

1. The hot end temperature controller is properly tuned. 
2. Your Gigabot's firmware is up-to-date. 
3. If the hot end temp is above 230°C, the part cooling fans should be off.

Measuring Heater Cartridge Resistance: 

1. Use a multimeter set to "Ω" to measure the resistance in ohms as outlined in the article "Testing the Heater Cartridge Resistance"
2. Record the measured values for the left and right pairs of wires.
3. The acceptable range of resistance is 8.6-10.6 ohms if using the standard multimeter probes.

Checking Heater Cartridge Voltage: 

Azteeg X3 Pro 

1. Use the Viki to set the left extruder temperature to 200°C by selecting "Control" > "Temperature" > "Nozzle 1."
2. While the hot end is heating, use a multimeter to check the voltage between the two terminals outlined in pink as marked below. Record this reading. 
3. Use the Viki to set the left extruder temperature to 200°C by selecting "Control" > "Temperature" > "Nozzle 2."
4.  While the hot end is heating, use the multimeter to check the voltage between the two terminals outlined in yellow as marked below. Record this reading. 

Azteeg x3 v2

1. Use the Viki to set the left extruder temperature to 200°C by selecting "Control" > "Temperature" > "Nozzle 1."
2. While the hot end is heating, use the multimeter to check the voltage between the two terminals outlined in pink as marked below. Record this reading. 
3. Use the Viki to set the left extruder temperature to 200°C by selecting "Control" > "Temperature" > "Nozzle 2."
4. While the hot end is heating, use a multimeter to check the voltage between the two terminals outlined in yellow as marked below. Record this reading. 

Checking Simplify3d Temperature Graph of the Hot Ends

1. Connect your Gigabot to a computer, and connect it to Simplify 3D.

2. Open the machine control panel (select the gear icon on the right side of the screen, second from the bottom) and ensure that the machine is communicating with the computer.

3. Select the temperature plot to bring up the graph shown in the photo below.

4.  In "Accessory Control" just to the right of that box (shown below) set the hot end temperatures (Tool 0 is the left hot end, and Tool 1 is the right hot end) to 200°C and start a timer.​

 5. Take screenshots of the temperature plot while the temperature of the hot ends is rising and when it levels off. Verify the temperature is stable within ±5°C from the temperature graph screenshot.

Questions or concerns? Reach out to our support team at support@re:3D.org or open a support ticket.