Display shows H1 or flashes a high temperature alarm; internal temperature is much higher than setpoint.

Safety: No internal electrical work is required for basic checks, but unplug the unit if you remove panels.

Steps:

• 1. Check door closure: Ensure the door is fully closing and the gasket is not obstructed by shelves or bottles. Verify the door switch (if present) is being pressed when the door closes.
• 2. Inspect door gasket: Look for gaps, tears, or warped sections of the gasket. Close the door on a sheet of paper; if it pulls out easily, the seal is weak in that area.
• 3. Verify ventilation: Confirm that the cooler has the required clearance around the sides, back, and top. Clean dust from the condenser coil and rear grille.
• 4. Check ambient temperature: Make sure the cooler is not installed in a very hot room or near heat sources (ovens, radiators, direct sun).
• 5. Listen for compressor: When calling for cooling, the compressor should run with a steady hum and the condenser should warm up. If the compressor does not run or only clicks, investigate the start relay and overload.
• 6. Monitor temperature: After correcting ventilation and door issues, allow 12–24 hours for the temperature to stabilize. If H1 persists and cooling is poor, there may be a sealed system issue (refrigerant leak or compressor failure).

Important: Sealed system repairs (refrigerant, compressor replacement) must be performed by a certified refrigeration technician.