Low temperature alarm (alternates with current cabinet temperature). H5: Parameter code related to alarm behavior and duration.
Don't guess when a red light flashes. The manual details specific error codes for: Sensor failures Communication timeouts Compressor state inconsistencies Pro-Tips for Maintenance mt3021 manual
To enter the system menu, press and hold for 5 seconds (displays "F1"). Parameter Code Description F1 Defrost duration 1–120 min F9 Compressor start delay 0–10 min H5 Alarm mode 4. Troubleshooting (Fault Codes) E1: Cabinet sensor failure. E2: Defrost sensor failure. mt3021 manual