Refrigerator display shows E0 and cooling performance is reduced or intermittent.

Safety first: Unplug the refrigerator from the wall outlet before removing any panels or touching wiring. If you are not comfortable working with live circuits or control boards, contact a qualified technician.

Step-by-step checks:

• Power reset: Unplug the refrigerator for 5 minutes, then plug it back in. This can clear a temporary communication error.
• Inspect main control board connections: Access the main PCB (usually at the rear behind a metal or plastic cover). Check that all multi-pin harnesses are fully seated and locked into the board.
• Look for damage: Examine the board for burn marks, swollen capacitors, or corrosion on connectors. Any visible damage usually means the board must be replaced.
• Check ground and neutral: Ensure the ground wire and neutral connections are tight at the board and terminal block.

If the E0 code returns after a reset and wiring check, the main control board is likely defective and should be replaced with the correct Hotpoint part number for your model.