Oven trips the circuit breaker or RCD as soon as it is turned on or when heating starts.

Safety first: Do not repeatedly reset a tripping breaker. Disconnect power and investigate the cause. Risk of fire or shock is present.

• Visual inspection: Remove rear and top covers. Look for burnt wires, melted insulation, or signs of arcing around elements and the terminal block.
• Element insulation test: With elements disconnected, use a megohmmeter (if available) to test resistance between each element terminal and chassis. Low resistance indicates earth leakage; replace the faulty heating element.
• Dry moisture: If the oven was recently cleaned with water or steam, allow it to dry thoroughly for 24 hours before retesting.

If you lack proper test equipment, have a qualified electrician or appliance technician diagnose the fault.