Unit stops cooling and shows E5; compressor does not start or shuts down quickly.

Safety warning: High voltage and refrigerant circuits are involved. Do not open the sealed refrigeration system. Unplug the unit before any inspection.

Basic checks:

• Ventilation: Ensure the condenser air outlet (rear or outdoor unit) is not blocked. Maintain at least 30–50 cm clearance around the unit.
• Clean condenser filter and coil: Remove and clean any rear filters. Gently vacuum or brush dust from the condenser coil fins.
• Room conditions: Avoid operating the unit in extreme ambient temperatures beyond Klarstein specifications, as this can trigger overload.

Component checks (advanced):

• Start capacitor: Access the compressor compartment and locate the start/run capacitor (usually a cylindrical can). Discharge it safely, then test capacitance with a meter. Replace with a Klarstein-compatible capacitor if out of tolerance or bulged.
• Compressor wiring: Inspect compressor terminals and wiring harness for burns or loose connections.
• Control board relay: Check for signs of overheating or pitting on the compressor relay on the main PCB. Replace the PCB if the relay is defective.

If E5 persists after airflow and capacitor checks, the compressor or refrigerant circuit may be faulty. This requires a licensed refrigeration technician.