Garbage disposal trips the circuit breaker or RCD immediately when switched on.

Safety first: Leave the breaker off and do not repeatedly reset an RCD that trips instantly; this can be a serious electrical fault.

• Inspect for leaks: Check around the base of the Rangemaster disposal for signs of water, rust streaks, or dampness. A leaking sink flange or cracked housing can allow water into the motor.
• Check the power cord: If your unit is plug-in, unplug it and inspect the cord for cuts, crushed sections, or burn marks. Replace the cord set if damaged.
• Drying out: If there is minor moisture but no obvious crack, leave the unit disconnected and allow it to dry for 24–48 hours, then test with an RCD-protected outlet. If it still trips, the motor is likely compromised.
• Do not open the sealed motor housing: Rangemaster motors are not user-serviceable. If the motor windings are shorted or there is internal earth leakage, the safe remedy is replacement of the disposal.
• Contact a qualified electrician: For persistent tripping or signs of burning, have the circuit and appliance tested with proper insulation and earth leakage testers.