Ice maker shows a low temperature or freeze protection error, water lines or reservoir freezing solid

Safety first: Disconnect power before testing sensors or control boards.

Steps to check:

• Inspect thermistor placement: Ensure the cabinet thermistor is mounted in the correct air path and not touching the evaporator plate directly, which can cause false low readings.
• Measure thermistor resistance: Remove and test the cabinet sensor at room temperature. Compare to Grundig's specified resistance curve. Replace if readings are significantly off.
• Check control relay: If the compressor runs continuously and never cycles off, the compressor relay on the main board may be stuck closed. In this case, the main control board should be replaced.
• Defrost frozen lines: Turn off the unit and allow all ice to melt from the reservoir and lines before restarting after repairs.

Warning: Do not operate the unit with known sensor faults; this can damage the sealed system.