York Millennium YCAS Series

Questions and Answers

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Ronald ValdezAug 8, 2025
How to troubleshoot no display on York Millennium YCAS panel?
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  Timothy HicksAug 8, 2025
  If there is no display on the panel and the York Chiller won't start, several issues could be the cause. First, ensure the main supply to the control system is switched on. Check that the control panel emergency stop switch and any remote emergency stop devices are in the ON position. Verify the mains supply and check for a tripped undervoltage relay. Inspect the emergency stop switch fuses, wiring from - T2 to the power board, and the fuse for the 24VAC supply to the power board. Finally, if there's no +12V output from the power board, consider replacing the power board or isolating any excessive load on it.
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stephengarciaAug 12, 2025
What to do if York Millennium YCAS Chiller displays HIGH AMBIENT TEMP fault?
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  Hannah PittsAug 12, 2025
  If the York Chiller displays a HIGH AMBIENT TEMP fault, it means the ambient air temperature is higher than the programmed operating limit. Use the ‘ambient temp.’ key to display the temperature and confirm that the displayed value is approximately correct. The warning message should clear when the ambient air temperature falls below the programmed operating limit. Also, check that the programmed settings are correct for the options fitted to the unit. Verify the fan is operating correctly with the correct rotation, and check for airflow recirculation. Finally, check sensor calibration, location and wiring, in case the measured temperature is incorrect.
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Courtney MccallAug 16, 2025
Why is my York Chiller showing a LOW WATER TEMP fault?
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  Joshua BaxterAug 17, 2025
  If the York Chiller displays a LOW WATER TEMP fault, it means the leaving liquid temperature is dropping below the programmed low limit faster than the unit can unload. Check for restrictions in the liquid flow line and ensure the liquid flow is stable. Also, the unit might not be unloading; check the supply to the unloader valve solenoid and confirm that the compressor unloads correctly. Finally, verify sensor calibration, location, and wiring, in case the measured temperature is incorrect.
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Brandon MartinezAug 21, 2025
Why does my York Chiller show SYS # HIGH OIL TEMP?
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  nathanlewisAug 21, 2025
  If the York Chiller displays a SYS # HIGH OIL TEMP message, it could be due to poor airflow through the condenser coils. Check for airflow restrictions caused by blockages on intake faces of air coils. Another possibility is that the measured temperature is incorrect, so check sensor calibration, location, and wiring.
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Julia DavisAug 26, 2025
What does NO RUN PERM mean on a York Millennium YCAS?
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  Richard MullinsAug 26, 2025
  If the York Chiller displays 'NO RUN PERM', it indicates a 'No run permissive' status. This can happen if there is no liquid flow through the cooler, so ensure that liquid pumps are running, valves are correctly set, and flow is established. Another cause could be that the flow switch contacts are not made. Check that the flow switch is functional and is installed according to the manufacturer’s instructions. On some systems, the pump starter may be wired to the unit and controlled to start by the unit.
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Chelsea MooreAug 29, 2025
What causes a LOW AMBIENT TEMP fault on a York Millennium YCAS?
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  Catherine JamesAug 29, 2025
  If the York Chiller displays a LOW AMBIENT TEMP fault, it means the ambient air temperature is lower than the programmed operating limit. Use the ‘ambient temp.’ key to display the temperature and confirm that the displayed value is approximately correct. The warning message should clear when the ambient air temperature rises above the programmed operating limit. You should also check the programmed settings to ensure they are correct for the options fitted to the unit. Check sensor calibration, location and wiring, in case the measured temperature is incorrect.
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Kevin Vincent MDSep 3, 2025
What does VAC UNDERVOLTAGE mean on my York Chiller?
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  Alexandra CollierSep 3, 2025
  If the York Chiller displays a VAC UNDERVOLTAGE fault, it indicates a poor mains supply voltage. Check that the mains supply is stable and within allowable limits. Also, check for voltage dip on compressor start.