Oven trips the household circuit breaker or RCD when heating starts

Safety first: Do not repeatedly reset a tripping breaker. Disconnect the oven from power and verify insulation resistance before further use.

• Visual inspection: Remove rear and top panels. Look for burnt wires, melted insulation, or signs of arcing around elements and terminal block.
• Test elements to earth: With all wires disconnected from each heating element, use a megohmmeter (preferred) or multimeter on high resistance range to measure between each element terminal and the metal chassis. Any low resistance indicates leakage; replace the affected element.
• Check wiring harness: Inspect where wires pass through metal holes or near sharp edges. Repair or replace any damaged sections and fit grommets where needed.
• Line filter: Test or temporarily disconnect the mains interference filter (if safe and according to wiring diagram) to see if tripping stops. Replace the filter if it is the source of leakage.

If you are not experienced with insulation testing and mains safety, contact a qualified technician.