Checks / troubleshooting:
• Communication cable may be
malfunctioning.
• Firmware on HEATER CONTROL board
may be malfunctioning.
• MAIN board may be malfunctioning.
• HEATER CONTROL board may be
malfunctioning.

Recommended actions:
1. Check the connection between MAIN board
and HEATER CONTROL board .
2. Check the connection between HEATER
JUNCTION board and HEATER CONTROL
board.
3. Check the version of the firmware and install
the latest firmware.
4. Replace HEATER CONTROL board or
MAIN board.