Display shows H1 and the temperature reading is extremely high or flashing, even though the interior feels cool.

Safety first: Unplug the unit before testing sensors or removing panels.

Steps to address H1:

• 1. Confirm actual temperature: Place an accurate thermometer inside the cooler to verify the real temperature. If the display shows much higher than actual, suspect the sensor circuit.
• 2. Inspect sensor wiring: Locate the cabinet NTC sensor and follow its wires. Look for crushed insulation, especially where the harness passes through the liner or behind panels.
• 3. Test sensor resistance: Disconnect the sensor from the board and measure resistance. A very low resistance (near 0 Ω) indicates a shorted sensor. Replace it with a new "STAIGIS cabinet NTC sensor".
• 4. Check harness for shorts: If the sensor tests normal, inspect the harness for spots where two wires may be touching bare copper or where the harness is pinched by screws or panels. Repair or replace the harness as needed.
• 5. Reset and test: After repairs, reconnect everything, plug in the unit, and verify that the H1 code clears and the temperature reading is realistic.

When to seek service: If wiring and sensor are good but H1 persists, the main control board may be defective.