To test a water temperature sensor, the following steps should be taken:
• Place the sensor in room temperature water and measure the output.
• Heat the water to a known temperature, such as 120°F (49°C), and measure again.
• Cool the water to a known lower temperature, such as 32°F (0°C), and measure again.
• Compare results against published specifications or calibrate if needed.
If all readings are within tolerance, then the sensor is working properly.