Thermistor
Common temperature-sensing fault part. Confirm resistance range and connector.
Hoshizaki E5 Error Code — What It Means
Hoshizaki error code E5 means high-temperature shutdown — the control board detected that ice machine temperatures rose above the safe operating limit during the freeze cycle and triggered a protective shutdown. On Hoshizaki KM and KML series cubers, the control monitors both evaporator and ambient temperatures. E5 typically indicates that the refrigeration system couldn’t maintain freeze cycle conditions within the expected time, or that the machine room ambient temperature exceeded the unit’s operating range. The machine will not make ice while E5 is active.
Common Causes
- High ambient temperature — Most Hoshizaki ice machines are rated to a maximum ambient of 100°F (38°C). Installations in hot kitchens, equipment rooms, or outdoor enclosures can exceed this limit during summer.
- Dirty condenser — A heavily fouled air-cooled condenser can’t reject heat effectively. Condensing pressure rises, the compressor runs hot, and the system can’t maintain freeze temperatures.
- Condenser fan motor failure — If the condenser fan stops running (failed motor, seized bearing, bad capacitor), the condenser temperature spikes immediately, triggering high-pressure and thermal limits.
- Inadequate ventilation — Ice machines recirculating their own hot exhaust air (too close to walls, in a cabinet without ventilation) experience artificially high ambient temperatures that trigger E5.
Step-by-Step Fix
- Check ambient temperature — Use a thermometer at the machine’s inlet air location. If the reading exceeds 95°F, improve room ventilation or relocate the machine before proceeding.
- Inspect and clean the condenser — Pull or vacuum the condenser coils. On air-cooled models, brush out lint and debris from between fins. A condenser that looks grey and matted needs cleaning.
- Check condenser fan operation — Confirm the fan runs during the freeze cycle. Listen for it or feel for airflow at the condenser outlet. If the fan doesn’t run, test the motor and capacitor.
- Verify ventilation clearances — Confirm the machine has the minimum clearances specified in the installation manual (typically 6 inches on sides, 12 inches on top for air-cooled models).
- Reset the system — Power cycle the machine after allowing it to cool. If E5 clears and the first freeze cycle completes normally, the fix worked.
Parts Often Needed
| Part | Notes |
|---|---|
| Condenser fan motor | Match OEM spec; Hoshizaki uses specific RPM and CFM ratings |
| Condenser fan blade | Replace if cracked or damaged; damaged blades reduce airflow significantly |
| Condenser coil cleaner | Nu-Calgon Coil King foam cleaner; rinse thoroughly |
Technician Tips
When diagnosing commercial refrigeration faults, start with the controller’s alarm history. Most digital controllers (Dixell, Carel, Eliwell) store the last 5-10 alarms with timestamps. An E1 alarm that appears consistently every few hours suggests a sensor going bad — the resistance value drifts until it’s out of range. An intermittent HI/LO alarm that appears only during hot afternoons suggests a condenser issue, not a sensor fault.
Prevention: Schedule quarterly condenser coil cleaning. Dirty coils are the #1 cause of high-head-pressure faults and compressor overheating in commercial refrigeration. Use a soft brush and compressed air — never a pressure washer on the coil fins.
Need Replacement Parts?
Before ordering, match the ice-machine part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If the condenser is clean, fan is running, and ambient temperature is acceptable, but E5 persists, the refrigerant system needs pressure testing. A certified refrigeration technician can diagnose high-side pressure and compressor condition.