Display shows H1 and interior temperature is much warmer than the setpoint.

Safety: No internal electrical work is required for basic checks; unplug only if removing panels.

• Check door closure: Ensure the Antarctic Star door is fully closing and the gasket is not obstructed by shelves or bottles.
• Inspect door gasket: Look for tears, warping, or gaps. Close the door on a sheet of paper at several points; if it pulls out easily, the seal is weak.
• Allow recovery time: If you recently loaded many warm bottles, allow 12–24 hours for temperature to stabilize. Avoid frequent door openings.
• Verify cooling operation: Listen for compressor and fans running. If they are off and H1 persists, there may be a control or compressor issue.
• Check ambient temperature: Ensure the cooler is in a room within the specified operating range (typically 41–95°F). Extreme heat can prevent proper cooling.
• Sensor and sealed system: If the unit runs constantly but never cools, the temperature sensor or sealed system (compressor/refrigerant) may be at fault. Sensor replacement is DIY-friendly; sealed system work requires a professional technician.