Display shows E3 and the compressor does not start or cycles erratically

Warning: High voltage is present at the compressor and control board. Unplug the wine cooler and do not touch live components.

Steps to address E3:

• Listen for compressor: After restoring power, listen for a humming or clicking from the compressor area. Repeated clicking without running suggests relay or start device issues.
• Inspect rear compartment: Unplug the unit, remove the rear lower access panel, and visually inspect the main control board for burnt spots, bulging capacitors, or melted relay housing.
• Check compressor start device: Carefully remove the start relay/overload from the compressor terminals. Shake it gently; if it rattles or smells burnt, it may be defective.
• Test continuity: Use a multimeter to check continuity through the start device according to Bosch specifications. Replace if open or shorted.
• Replace control board: If the start device is good but the board shows damage or does not send power to the compressor (requires live testing by a professional), the main control module should be replaced.
• Reassemble and test: Reinstall the access panel, restore power, and monitor for normal compressor operation and disappearance of the E3 code.

Professional help: Because compressor and live-voltage diagnostics are hazardous, most homeowners should contact a Bosch-authorized technician for E3 faults.