Display shows SPTS; the heater will not start or overshoots the set temperature.

Note: A faulty water sensor can cause inaccurate temperature readings and improper cycling.

• Locate sensor: On the SmartPool header, find the thermistor or probe labeled water/inlet sensor.
• Inspect connection: With power off, unplug and replug the sensor connector at the control board to clean contacts.
• Check seating: Ensure the sensor is fully inserted into its well or port and secured with the retaining clip.
• Compare temperatures: Use a separate thermometer at a nearby return jet to compare actual water temperature to the heater display. Large discrepancies indicate sensor issues.
• Replace if needed: If SPTS persists, replace the SmartPool water temperature sensor.