Ice-O-Matic GEM / MFI nugget and flake
Auger-type machines with a control board carrying seven indicator lights, infrared ice level sensors in the chute, a reservoir water sensor and high and low pressure cut-outs.
What it is: Nugget / flake ice machine. GEM0450–GEM0956 and MFI0500–MFI1256 (GEM-MFI service manual).
Key combo: No service menu. Read the board lights. Reset an auger overload shutdown by switching power off and on.
Ice-O-Matic GEM / MFI nugget and flake error codes
| Code | Meaning | Likely cause | How to reset |
|---|---|---|---|
| Power OK light off | No control power, or a pressure cut-out is open | No supply, high or low pressure switch open, failed board | Check supply and both cut-outs. If both are closed and the light stays off, replace the board. |
| Water OK light off | Reservoir water below the sensor tip | Water supply, float valve, dirty or open water sensor | Restarts by itself once water returns. Test the sensor with an ohmmeter (near zero ohms to the tip). |
| Service light blinking | Auger motor current too high; restart attempt in 4 minutes | Scale on the evaporator, worn bearings, gear motor | Automatic retry (twice). |
| Service light on steady | Auger motor overloaded again after two restarts | Same as above | Manual reset: switch power off and back on. |
| Bin full light on | Ice blocked the infrared beam for 6 s or more | Bin full, or scaled sensors | Restarts after the beam is clear for 10 s. Clean the sensors if needed. |
| Machine off, all lights normal | High or low pressure cut-out open | Dirty condenser, fan, water valve, low charge | Both cut-outs reset by themselves when pressure recovers. |
Service values
| Code | What it does | Range | Default / typical |
|---|---|---|---|
| High pressure cut-out | Automatic reset | — | 450 psig |
| Low pressure cut-out | Automatic reset | — | 15 psig |
| Start delay | After switching on | fixed | 10 s |
| Auger run-on | After the compressor stops | fixed | 1 min |
| Compressor restart delay | Minimum off time | fixed | 2 min |
| Auger amps (typical) | GEM0450/MFI0500 and GEM0650/MFI0800 115 V | — | 4.6 A |
| Auger amps (typical) | 230/50 models | — | 2.0–2.3 A |
| Remote low side / discharge | Typical | — | 28–35 / 220–275 psig |
Notes
- When checking cut-outs: if the high pressure switch is open with discharge below 300 psig, or the low pressure switch is open with suction above 20 psig, the switch itself is faulty.
For licensed technicians only. This equipment can involve mains voltage, high-voltage microwave circuits, gas and refrigerant. Isolate power (and gas) before opening panels, follow the manufacturer's manual and your local licensing rules (for example ARC refrigerant handling and electrical or gas licences). Wrong settings can spoil food or damage equipment. Check every value on the unit in front of you before changing it.
Based on: Ice-O-Matic GEM-MFI series service manual. Always check the manual for your exact model and software version.
ServiceModes is not affiliated with Ice-O-Matic or any other manufacturer. Written in our own words from the manufacturer's documentation.