Display shows unrealistic ambient or water temperatures but no specific error code.

Safety first: Turn off power before adjusting or replacing sensors.

• Compare readings: Use a reliable thermometer to compare actual water and air temperatures to the displayed values.
• Improve contact: Ensure pipe sensors are tightly strapped with insulation over them, and air sensors are in free air away from heat sources.
• Inspect connections: Clean and reseat sensor connectors on the main PCB.
• Replace drifting sensors: If a sensor consistently reads far off, replace it with the correct SPRSUN NTC sensor.