Display shows E4 and the unit may not defrost properly or may run continuously.

Safety first: Disconnect power before accessing the evaporator or control board. Risk of electric shock and sharp edges.

E4 is commonly associated with a defrost sensor or defrost circuit problem.

• Step 1 – Inspect for heavy frost: Remove internal panels to view the evaporator. If it is encased in ice, the defrost system is likely not working.
• Step 2 – Check defrost sensor: Locate the defrost NTC (often clipped to the evaporator tubing). Inspect for damage and secure mounting. Test resistance and replace if out of spec.
• Step 3 – Test defrost heater (advanced): With the unit unplugged, disconnect the heater leads and measure continuity. An open circuit indicates a failed heater that must be replaced with a EuroCave-compatible defrost heater.
• Step 4 – Inspect wiring and connectors: Look for burnt connectors, melted insulation, or loose plugs between heater, sensor, and control board.
• Step 5 – Control board check: If sensor and heater test good, the defrost relay or triac on the main control board may be faulty. This typically requires board replacement.
• Step 6 – Manual defrost: As a temporary measure, fully defrost the unit, then restart and monitor. If E4 returns, proceed with component replacement.

Warning: Do not bypass the defrost safety devices. Improper modifications can cause overheating and fire risk.