Hoshizaki Ice Machine Beep Codes (KM Crescent Cubers)
Error, alarm and light codes explained
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Updated October 14, 2026
Quick answer
On Hoshizaki KM crescent cubers, 1 beep means high evaporator temperature, 2 beeps means the harvest backup timer tripped, and 3 beeps means the freeze timer tripped. 6 and 7 mean low or high supply voltage. 4 and 5 beeps only exist on older KM models with a mechanical bin control. Reset 1-3 beeps with the ALARM RESET button on the control board while it is beeping.
Which machines this page covers
These alarms come from Hoshizaki's service manuals for current KM modular crescent cubers: Service Manual 73213 (KM-901M_J, KM-1100M_J, KM-1340M_J, KM-1601MRJ; revised 3-20-2026) and Service Manual 73230 (KM-350M_J, KM-520M_J, KM-660M_J; revised 5-12-2021). The 4- and 5-beep alarms come from Hoshizaki Service Bulletin SB01-0001 for older KM-280, KM-500, KM-630 and KM-900 models.
Hoshizaki's square-cube (IM), flaker (F) and nugget (DCM) machines use different controls. Their codes are not the same as the KM beep table.
Hoshizaki KM alarm table
| Beeps | Alarm (per Hoshizaki) | What triggers it | Reset |
|---|---|---|---|
| 1 | High evaporator temperature | Evaporator temperature above 127°F (53°C) | ALARM RESET button, power on |
| 2 | Harvest backup timer | Harvest longer than 20 minutes, two cycles in a row | ALARM RESET button, power on |
| 3 | Freeze timer | Freeze longer than the freeze timer setting, two cycles in a row | ALARM RESET button, power on |
| 4 | Bin control short (older KM with mechanical bin control) | Short circuit at the red K-4 connector | White ALARM RESET button while beeping |
| 5 | Bin control open (older KM with mechanical bin control) | Open circuit at the red K-4 connector | White ALARM RESET button while beeping |
| 6 | Low voltage | Control voltage about 92 VAC or less | Resets automatically when voltage is corrected |
| 7 | High voltage | Control voltage about 147 VAC or more | Resets automatically when voltage is corrected |
| Red LED blinks | Freeze-time correction (some boards) | Maximum freeze time differential exceeded; after 3 corrections in 36 hours the yellow EXT HARVEST LED also blinks | Technician completes Hoshizaki's freeze-up checklist |
The alarm repeats as a group of beeps every 3 seconds. Count the beeps in one group.
1 beep: high evaporator temperature
The evaporator got hotter than 127°F. That normally only happens if harvest heat keeps running. Hoshizaki's manual lists a stuck hot gas valve or relay, hot water entering the machine, a stuck headmaster valve, or a shorted thermistor. An owner can check one thing: that the machine is connected to the cold water line, not a hot or mixed supply. The rest is technician work.
2 beeps: harvest backup timer
Harvest ran longer than 20 minutes twice in a row. The ice is not releasing, or the board is not seeing harvest end. Causes in the manual include an open thermistor, a hot gas valve that is not opening, a leaking expansion valve or liquid line valve, low refrigerant charge, an inefficient compressor, or a leaking water regulating valve on water-cooled units.
3 beeps: freeze timer
The freeze cycle ran past the timer limit twice in a row. This is the most common Hoshizaki alarm, and the manual's cause list starts with the water side:
- Float switch stuck closed (up), often from scale. Hoshizaki's cleaning procedure includes the float switch.
- Inlet water valve leaking by, so the sump keeps refilling with warm water.
- Pump motor not pumping water over the evaporator.
- Refrigeration causes: hot gas valve leaking by, expansion valve defective, liquid line valve not opening, low charge, headmaster not bypassing, inefficient compressor.
The freeze timer length is set with dip switches on the control board, and Hoshizaki sets it at the factory per model. Do not change dip switches to silence a 3-beep alarm: the manual warns that non-factory settings can affect performance and warranty coverage.
A related trap from Hoshizaki Service Bulletin SB04-0008: on older KM machines converted from a mechanical to a thermostatic bin control, wrong wiring can make the machine cycle on the 3-beep alarm.
4 and 5 beeps: mechanical bin control (older models)
Hoshizaki introduced a mechanical "flapper" bin control with a magnetic proximity switch on KM-280, KM-500, KM-630 and KM-900 machines in 2001. It plugs into the red K-4 connector, and with dip switch 7 on, the board adds two alarms: 4 beeps for a short circuit and 5 beeps for an open circuit at K-4.
Owner checks: make sure the flapper moves freely and is not jammed by ice or tape (new units ship with it taped in the bin-full position). Wiring and connector faults are for a technician.
6 and 7 beeps: supply voltage
These are not ice-making faults. The board shuts down when control voltage drops to about 92 VAC or rises to about 147 VAC, and restarts on its own once voltage is normal. Repeated 6- or 7-beep alarms point to a building electrical problem: a shared circuit, a loose connection, or utility voltage swings. An electrician should check the circuit.
How to reset a Hoshizaki
- Count the beeps and write the number down. The technician will need it.
- With power on, press the ALARM RESET button on the control board while it is beeping. The machine restarts at the 1-minute fill cycle.
- Watch the next full cycle. If the same alarm returns, stop resetting and call for service.
The control board sits behind the front panel, near live terminals. Hoshizaki's manual warns of electric shock risk. If you are not comfortable opening the panel, leave it to a technician.
When to call a technician
Call a technician if 1, 2 or 3 beeps return after one reset, if you hear 4 or 5 beeps, or if the red POWER OK LED is blinking. Call an electrician for repeated 6- or 7-beep alarms.
Open 7 days, 8 AM to 5 PM, with emergency service until 9 PM. CA Lic. #776244.
Frequently asked questions
What does 3 beeps mean on a Hoshizaki ice machine?
On a KM crescent cuber, 3 beeps means the freeze timer tripped: the freeze cycle ran longer than its setting two cycles in a row. Scale on the float switch and water supply problems are common causes.
How do I reset a beeping Hoshizaki?
With power on, press the ALARM RESET button on the control board while it is beeping. Voltage alarms (6 and 7 beeps) reset by themselves once voltage is normal.
Does every Hoshizaki use the same beep codes?
No. The beep table applies to KM crescent cubers. Square-cube, flaker and nugget models use different controls, and 4- and 5-beep alarms only exist on older KM units with a mechanical bin control.
Can I change the dip switches to stop the alarm?
No. Hoshizaki sets the dip switches at the factory and warns that changing them can hurt performance and affect warranty coverage.
Related guides
Sources
- Hoshizaki Service Manual 73213: KM-901M_J, KM-1100M_J, KM-1340M_J, KM-1601MRJ (revised 3-20-2026)
- Hoshizaki Service Manual 73230: KM-350M_J, KM-520M_J, KM-660M_J (revised 5-12-2021)
- Hoshizaki Service Bulletin SB01-0001: Mechanical bin control, KM-280/500/630/900 (March 23, 2001)
- Hoshizaki Service Bulletin SB04-0008: Mechanical to thermostatic bin control conversion (July 18, 2004)
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