Koolaire Ice Machine Safety Limit 1: Freeze Time Reached 60 Minutes
Safety Limit 1 means the freeze time reached 60 minutes, so the board started a harvest. After 6 consecutive 60-minute freeze cycles the machine stops. Press On/Off and start a new ice making cycle to reset it, and call for service if it repeats.
High: after six long freeze cycles the machine stops making ice.
- Code
- Safety Limit 1 (Service light flashing)
- Maker
- Koolaire
- Equipment
- Ice machines
- Applies to
- Koolaire KT series control board
What does Koolaire Safety Limit 1 mean?
Making ice depends on the evaporator getting cold enough, fast enough. The control board times every freeze cycle. If a freeze reaches 60 minutes, the board treats it as a limit and starts a harvest instead of waiting any longer, and the board shows the Service light flashing on the control board (Safety Limit 1). One such cycle does not stop the machine. After 6 consecutive 60-minute freeze cycles, the board stops the ice machine so it does not keep running without making ice. The manual lists no individual causes in this section. It gives the reset: press the On/Off button and start a new ice making cycle. Its troubleshooting page says to switch OFF and then ICE, and if the machine restarts and the condition repeats, to call for service. A long freeze is a sign of heat not leaving the evaporator, whether from air, water, refrigerant or the water supply, so the cause lies in the refrigeration side of the machine.
Affected models and control systems
Koolaire KT modular ice machines: KDT and KYT 0300A, 0400, 0420, 0500, 0700, 1000 and 1700 in air-, water- and remote-cooled versions.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Service light flashing on the control board
- Very small or thin ice, or none in the bin
- Machine stopped after a long series of cycles
Possible causes
Likely causes — what usually sits behind Safety Limit 1 on this control. A technician confirms which one it is before any part is replaced.
- A condenser clogged with dust and grease so heat cannot leave the system
- Water-cooled supply too warm or too weak to carry heat away
- Low refrigerant charge slowing the cooling of the evaporator
- Incoming water much warmer than normal in a hot kitchen in summer
Safe checks before calling for service
- Press the On/Off button, then start a new ice making cycle.
- Check that the air flow around the machine is open and the condenser is not covered in dust.
- On a water-cooled unit, confirm the water supply to the condenser is on.
- If the Service light flashes again, note how many hours it ran and call for service.
How a technician diagnoses Safety Limit 1
- Read the light state and ask how long the machine ran before the limit.
- Check air flow or water flow through the condenser.
- Measure suction and discharge pressures and compare with the manual's chart.
- Check the water supply and the evaporator for scale or ice buildup.
- Check the refrigerant charge and the water inlet valve operation.
- The refrigeration circuit holds refrigerant that needs certified handling.
- Pressure readings need gauges on the live system.
- Condenser and compressor circuits run on line voltage.
How Safety Limit 1 differs from similar codes
Safety Limit 2 concerns harvest cycles of 3.5 minutes; Safety Limit 1 concerns freeze cycles of 60 minutes.
Technical reference
- Maker documentation
- Koolaire owner support
- Edition
- Part Number 000014142 Rev 04 07/22
- Models / control
- Koolaire KT series control board
- Section
- Section 3 Operation, Safety Limits (p. 27); Section 5 Troubleshooting, Safety Limit Feature (p. 41)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Koolaire ice machine error codes
Does Safety Limit 1 stop the machine at once?
No. It starts a harvest, and the machine stops after 6 consecutive 60-minute freeze cycles.
How do I reset it?
Press On/Off and start a new ice making cycle.
Will it clear itself?
Not if the cause is still there.
Need help with Koolaire Safety Limit 1?
A technician confirms the cause on site and gives you the price in writing before any work starts.