Sensor failures in heat pump water heaters can lead to a range of issues, from erratic temperature control to complete system shutdowns. Understanding how to diagnose and fix these failures is crucial for maintaining the efficiency and reliability of your heating system. This infographic outlines the key steps and considerations for identifying and addressing sensor problems in heat pump water heaters.

Identifying the Faulty Sensor:

  • Temperature Sensor: Symptoms include incorrect water temperature readings, either too hot or too cold.
  • Pressure Sensor: Look out for pressure warnings on the display panel, indicating the system is operating outside normal pressure ranges.
  • Flow Sensor: Reduced water flow or error messages related to water circulation could signal a flow sensor issue.

Diagnostic Steps:

  1. Safety First: Turn off the power supply to the heat pump water heater to prevent electrical hazards.
  2. Locate the Sensors: Use your heater's manual to find the location of each sensor within the system.
  3. Test Sensor Functionality: Using a multimeter, test each sensor for proper operation. Faulty sensors often show abnormal resistance or no continuity.
  4. Replacement: For any sensor that tests outside of normal parameters, carefully remove and replace it with a manufacturer-approved part.

Key Tips:

  • Always consult your heat pump water heater's manual for specific guidance on sensor locations and specifications.
  • When replacing sensors, ensure all connections are secure and that the new sensor is compatible with your system.
  • After replacing sensors, monitor your heat pump water heater closely for the first few cycles to ensure normal operation.


Diagnosing and fixing sensor failures in heat pump water heaters requires careful attention to detail and a methodical approach. By understanding the common symptoms of sensor issues and following the steps outlined in this guide, homeowners and technicians can effectively resolve these problems, ensuring their heat pump water heaters continue to operate efficiently and reliably.