GE heat pump water heater shows F2 and shuts down or runs only in limited modes.

Safety: Turn OFF power at the breaker before opening any panels.

Steps to address F2:

• Locate the ambient sensor: On GE heat pump water heaters, the ambient thermistor is usually mounted near the evaporator coil or air intake grille in the upper heat pump section.
• Inspect wiring and connector: Remove the upper cover, locate the small sensor probe and its two-wire harness. Check for damage, rubbing on sharp metal, or rodent damage. Reseat the connector at the control board.
• Test the sensor: With power off, disconnect the sensor and measure resistance with a multimeter. Compare to GE’s temperature/resistance chart. An open circuit or near-zero resistance indicates a bad sensor.
• Check for blockage: Ensure the air intake and exhaust are not blocked by dust, insulation, or stored items, which can cause abnormal temperature readings.
• Reset and test: Restore power and see if F2 clears. If the code returns and the sensor tests good, suspect a control board issue.
• Replace as needed: Replace the ambient thermistor if readings are out of spec. If wiring and sensor are good, replace the control board.

Note: Some GE models will limit operation or switch to electric elements only when this sensor fails.