HI on CAREL UltraCella: meaning and checks

First checks, in order

The checks below are a REFTHE editorial path to compare with the machine diagram, configuration and manual.

1. Compare the displayed temperature, independent measurement, configured threshold and delay.
2. Record cycle state, load, doors, defrost and fans when the alarm occurs.
3. Find the cause of the actual temperature before changing thresholds or clearing history.

What the code does not prove

The code directs the investigation but does not, by itself, prove that a probe, valve, controller or other component is faulty.