Dryer trips the household circuit breaker or RCD when starting or during heating

Safety first: Do not repeatedly reset a tripping breaker. Unplug the dryer and investigate or call a professional.

• Visual inspection: Remove the rear panel and inspect the heater, wiring, and motor for signs of burning, charring, or moisture.
• Test heater to earth: With a multimeter, check resistance between each heater terminal and the metal chassis. Any low resistance indicates a short; replace the heater.
• Check for leaks: On condenser/heat pump models, look for water leaks near electrical parts. Fix leaks and dry components thoroughly.
• Professional insulation testing: If no obvious fault is found, a qualified technician should perform insulation resistance tests to locate the leakage.