Oven displays E5 and heating is disabled; sometimes appears after a power surge.

Safety first: Switch off the circuit breaker before opening any panels. High voltage is present inside the oven.

Steps to check:

• Verify household supply: Use another appliance or a multimeter (if qualified) to confirm that the mains voltage is within the normal range specified on the oven rating plate.
• Inspect power terminal block: Remove the rear cover to access the power terminal block where the mains cable connects. Check for loose screws, discoloration, or melted plastic. Tighten any loose terminals and replace the block if damaged.
• Check line filter module: Many OBH Nordica ovens use an EMI line filter near the power entry. Inspect it for burn marks or bulging components. Replace if visibly damaged.
• Control board power supply: If external power is stable, the low-voltage power supply on the main PCB may be faulty. Look for swollen capacitors or burnt components. Replacement of the main control board is usually required rather than component-level repair.
• Power reset: After any corrections, leave the oven disconnected for 5–10 minutes, then restore power and check if E5 clears.

Note: If your home has frequent voltage fluctuations, consider using a dedicated circuit or consulting an electrician to stabilize the supply.