Why won't my RCD reset?

Why Won't My RCD Reset? An RCD (Residual Current Device) is a safety switch in your consumer unit (fusebox) that trips automatically when it detects electricity leaking to earth — which could mean danger to life. When it won't reset, it almost always means the fault is still there. Forcing it to stay on isn't possible by design, and that's protecting you. What Does the RCD Actually Do? It monitors the balance of electrical current flowing in and out of a circuit. If more than 30 milliamps goes missing (leaking through a fault or through a person), it cuts power in under 40 milliseconds. Safe Checks You Can Do Yourself Unplug every appliance connected to circuits protected by the tripped RCD — including lamps, phone chargers, kettles, washing machines, and TVs Switch off all lighting circuits on the affected side if you can identify them Try to reset the RCD — push it firmly up (or press the reset button depending on your board type) If it holds, plug appliances back in one at a time, waiting a few seconds each time, until the RCD trips again — that appliance is faulty Check for obvious signs — burn marks on sockets, smell of burning, a circuit that was wet (outdoor socket after rain, kitchen splash) Common Causes A faulty appliance (washing machines and dishwashers are frequent offenders) A damaged extension lead or adaptor Water ingress into an outdoor socket, light fitting, or shower unit Worn wiring insulation causing an earth fault A faulty RCD itself (less common but possible) When You Must Call an Electrician The RCD still won't reset after unplugging everything It trips again immediately when you reset it You can smell burning or see scorch marks The fault is in a bathroom, kitchen, or outdoor circuit The RCD trips repeatedly over several days Never bypass or tape up an RCD. It exists to prevent fatal electric shock and fire. If in doubt, leave the circuit off and call a Part P registered electrician.