The display shows 'ICE' or 'IC', and pumps run automatically even when the spa is not in use.

Note: 'ICE' is usually a protective mode, not a fault. The spa is trying to prevent freezing damage.

• Check actual water temperature: Use a separate thermometer to confirm if the water is near 40°F (4–5°C). If so, this is normal operation.
• Ensure cover is on and sealed: A well-fitted Artesian spa cover helps maintain temperature and reduce freeze risk.
• Verify filtration/heating schedule: Confirm that the spa is programmed correctly and not set to an excessively low setpoint in cold weather.
• If 'ICE' appears in warm conditions: The temperature sensor may be reading incorrectly. Follow the steps for 'Sn1' to inspect and possibly replace the sensor.

Do not disable freeze protection. If the spa runs constantly in mild temperatures with an 'ICE' indication, have the sensor and control board checked.