Safety first: Unplug the freezer before removing interior panels.

Locate freezer sensor: Typically behind a small cover on the interior wall or attached to the evaporator cover.
Inspect and test: Remove the cover, disconnect the sensor, and measure resistance. Compare to Haier's NTC chart. Replace if out of range.
Check connector: Clean and reseat the connector at both the sensor and the main board.
Board diagnosis: If a new sensor does not clear F1, the main control PCB sensor circuit may be defective and require replacement.

Freezer shows F1 and may not maintain set temperature.

Possible Causes