E01 : High Fluid Temperature

Troubleshooting this equipment requires access to parts that may cause electric shock or other serious injury if work is not performed properly. Have a qualified electrician perform all electrical troubleshooting. Be sure to shut off all power to the equipment before repairing.


NOTE: Before checking the thermocouple, note which zone (ISO or RES) has high fluid temperature.

  • Thermocouple ISO or RES senses a fluid temperature above 260°F (71°C). 
  • Overtemperature switch ISO or RES senses a fluid temperature above 230°F (110°C) and opens. At 190°F (87°C) the switch closes again. 
  • Thermocouple ISO or RES fails, is damaged, is not touching the heater element, or has a poor connection to the temperature control board.
  • Overtemperature switch fails in the open position. 
  • The temperature control board fails to turn off any heat zone.
  • Zone power wires or thermocouples are switched from one zone to another.
  • Failed heater element where thermocouple is installed. 
  • Loose wire
  1. Check that connector B is firmly plugged into heater control module. See Temperature Control Modules Connections, in manual.
  2. Clean and re-plug connections.
  3. Check connections between the temperature control module and overtemperature switch, and between the temperature control module and thermocouples. Ensure all wires are securely connected to connector B on heater control module. See Table 7, in manual.
  4. Remove connector B from heater control module and check continuity of thermocouples by measuring resistance across pins on the plug end.
  5. Verify fluid temperature, using an external temperature sensing device.
  6. Check if thermocouples are damaged, or not contacting the heater element, see FIG. 16, in manual.
  7. Check if temperature control module turns off when equipment reaches temperature setpoint: 
    1. Set temperature setpoints far below displayed temperature. 
    2. Turn zone on. If temperature rises steadily, power board is failing. 
    3. Verify by exchanging with another power module. See Replace Temperature Control Modules, in manual. 
    4. If the exchanged module does not fix the problem, the power module is not the cause.
  8. Verify continuity of heater elements with an ohmmeter, see manual.